How to fix "The application was unable to start correctly" error 0xc000012d in Windows?

Error 0xc000012d means Windows ran out of virtual memory: the programs already running have used up the commit limit, so a new one cannot start. It is a memory and page file problem, not a broken program. Close what uses the most memory first, then let Windows manage the page file again.

Facts checked on 15 October 2026. Steps written for Windows 11 (25H2 and 26H2) and Windows 10 22H2.

What error 0xc000012d "The application was unable to start correctly" means

The full message reads: The application was unable to start correctly (0xc000012d). Click OK to close the application. Unlike most codes shown in this window, this one names its cause plainly. In Microsoft's NTSTATUS list, 0xC000012D is STATUS_COMMITMENT_LIMIT, with the text "{Out of Virtual Memory} Your system is low on virtual memory. To ensure that Windows runs correctly, increase the size of your virtual memory paging file."

• Commit limit: Microsoft defines it as the sum of physical memory and all page files. Task Manager shows it as the second number of Committed, for example 14.2/15.8 GB.
• Commit charge: the memory all running programs have reserved. When it reaches the limit, Microsoft says processes might not get committed memory, which can cause freezing, crashing and other malfunctions.
• Why a new program fails first: a program that is starting must reserve memory before it can draw a window. With nothing left to reserve, Windows stops it and shows this window.
• Why it names WerFault.exe: when a running game or program crashes for the same reason, Windows starts its error reporter, WerFault.exe. That process needs memory too, so it can fail with the same code.

Why Windows runs out of virtual memory and shows 0xc000012d

Only two things can cause the error: the limit is too low, or the programs use too much. The table ranks the usual reasons. Microsoft's text for the code points at the first group, the page file.

How to read Committed in Task Manager before you change anything

One number tells you which group of fixes you need. Press Ctrl + Shift + Esc, open Performance and select Memory. Read the Committed value, shown as two numbers: what is in use and the limit.

How to fix "The application was unable to start correctly" error 0xc000012d

Fix 1 frees memory now and shows what used it. Fixes 2 to 4 raise the limit through the page file and fix most cases for good. Fixes 5 to 7 are for a program that keeps eating memory or when memory is not the cause.

Fix 1. Check memory use in Task Manager and close the program that uses the most

5 minutesLow riskEveryone, right after the error appears. It also tells you which of the other fixes you need.

The code means the commit limit is reached at this moment. Closing the program that has reserved the most memory gives some of it back at once, and the Commit size column shows which program that is.

1. Press Ctrl + Shift + Esc to open Task Manager.
2. Select Performance, then Memory, and write down the Committed value, for example 15.1/15.8 GB.
3. Select Details. Right-click any column heading, choose Select columns, tick Commit size and select OK.
4. Select the Commit size heading to sort the list, largest first.
5. Save your work in the program at the top of the list, then close it normally. If it does not respond, select it and select End task.
6. Check Committed again, then start the program that showed the error.

Fix 2. Let Windows manage the page file size again

10 minutesLow riskThe commit limit is about the same as your RAM, or someone changed the virtual memory settings before.

Microsoft's text for 0xc000012d tells you to increase the paging file. A system-managed page file grows by itself when the commit charge reaches 90 percent of the limit, so the limit rises before programs start to fail.

1. Press Win + R, type SystemPropertiesAdvanced and select OK.
2. On the Advanced tab, under Performance, select Settings.
3. Open the Advanced tab of Performance Options and, under Virtual memory, select Change.
4. Tick Automatically manage paging file size for all drives.
5. Select OK in each window, then restart the PC.
6. After the restart, open Task Manager again and check that the commit limit is now larger than your RAM.

Fix 3. Free space on drive C: so the page file can grow

10 to 20 minutesLow riskDrive C: is nearly full, or Windows warns about low disk space.

A system-managed page file lives on a drive and grows only into free space on it. Microsoft caps that growth at one eighth of the volume size, so on a small or full drive C: the limit stays low however you set it.

1. Open File Explorer, select This PC and check the free space under Local Disk (C:).
2. Remove temporary files and old update files with Storage Sense or Disk Cleanup, as shown in the procedure below.
3. Move large videos, game installs or downloads you do not need on C: to another drive.
4. Restart the PC and check the commit limit in Task Manager again.

Step by step with screenshots: Free up disk space and delete temporary files.

Fix 4. Set a larger custom page file for heavy games and editors

10 minutesLow riskGames, video editors or 3D tools still hit the limit with a system-managed page file.

A system-managed page file grows to three times the RAM or 4 GB, whichever is larger, and no more than one eighth of the drive. A fixed size gives the limit room at once, without waiting for it to grow during a game.

1. Open the Virtual memory window again, as in Fix 2 (Win + R, SystemPropertiesAdvanced, Settings, Advanced, Change).
2. Clear the tick at Automatically manage paging file size for all drives.
3. Select drive C:, or a second internal drive with more free space, and choose Custom size.
4. Enter an Initial size (MB) of at least the RAM in MB, for example 16384 for 16 GB.
5. Enter a Maximum size (MB) of up to three times the RAM, as far as the drive's free space allows, for example 49152 for 16 GB.
6. Select Set, then OK, and restart the PC.

Fix 5. Update or replace the program that keeps taking more memory

15 minutesLow riskCommitted keeps rising over hours, and the same program sits at the top of the Commit size list each time.

A program with a memory leak reserves memory and never gives it back. No page file is big enough for it in the end. A newer version from its maker is the only real cure, and a restart only resets the count.

1. Restart the PC and open Task Manager on the Details page with the Commit size column, as in Fix 1.
2. Use the PC as usual and look again after an hour or two. Note the process whose commit size keeps growing.
3. Right-click that process and select Open file location to see which program it belongs to.
4. Install the newest version from the maker, or the newest driver if it is a driver tool from your graphics, audio or RGB vendor.
5. If there is no fix and you do not need the program, uninstall it in Settings > Apps > Installed apps.

If the process starts with Windows, you can stop it from starting until its maker ships a fix: Stop apps from opening at startup.

Fix 6. Start Windows with a clean boot to find a background memory user

20 minutesLow riskMemory fills up although no program in the Commit size list stands out, or the culprit is a service.

Background services do not show as apps, and some of them, such as old system tools and RGB or tuning utilities, can hold memory. A clean boot starts Windows without them, so you see whether the limit is still reached.

1. Open System Configuration. Select Search on the taskbar, type msconfig and select System Configuration from the results.
2. Hide Microsoft services. On the Services tab, select the Hide all Microsoft services check box. Only services from other companies stay in the list.

   

3. Disable the remaining services. Select Disable all, then select Apply.
4. Open Task Manager. On the Startup tab of System Configuration, select Open Task Manager.

   

5. Disable the startup apps. On the Startup apps tab in Task Manager, select each item whose status is Enabled and select Disable. Write down or take a screenshot of the items you disable: you need the list to turn them back on.

   

6. Confirm the changes. Close Task Manager. On the Startup tab of System Configuration, select OK.
7. Restart and test. Restart the PC. Windows now starts in a clean boot environment: try again the thing that failed (run the app, install the update, uninstall the program).

These steps were written for Windows 11 25H2 and 26H2. The full page with the other versions and what each result means: How to perform a clean boot in Windows

If memory stays low in the clean boot, turn the services back on in small groups until Committed starts to grow again. The last group holds the cause. Update that tool or remove it.

Fix 7. Repair Windows system files with SFC and DISM

20 to 30 minutesNo riskMemory is far below the limit, the page file is fine, and programs still fail with 0xc000012d.

With enough memory free, the out of memory code is unusual. Damaged Windows memory management files are a rare cause, and SFC with DISM checks them without changing anything on a healthy PC, so it comes last.

1. Open an elevated command window. Right-click Start and select Terminal (Admin), or type cmd in the search box, right-click Command Prompt and select Run as administrator. Select Yes when Windows asks for permission.

   

2. Run DISM first. Type the command below and press Enter. DISM downloads clean copies of damaged components from Windows Update, so it can take several minutes. Wait until it says The operation completed successfully.

   DISM.exe /Online /Cleanup-Image /RestoreHealth

   

3. Run System File Checker. In the same window, type the command below and press Enter. Do not close the window until the verification reaches 100%.

   sfc /scannow

   

4. Read the result and restart. Compare the last message with the table below this guide, then restart the PC so that repaired files are loaded.

   

These steps were written for Windows 11 24H2 and 25H2. The full page with the other versions and what each result means: Run DISM and SFC to repair Windows system files

If error 0xc000012d still appears

If the commit limit is reached with a working page file, free disk space and no leaking program, the PC has too little memory for the work it does. That is a hardware limit, not a fault in Windows.

• Compare RAM with the program's needs. Games and editors list their minimum and recommended RAM. A PC at the minimum hits the limit quickly with a browser open in the background.
• Check the RAM Windows sees. In Task Manager, Memory shows the installed size. If it is less than the PC has, a module may be loose or faulty. Test it with How to test your RAM with Windows Memory Diagnostic.
• On a laptop with shared graphics, part of the RAM goes to the graphics chip and is not available to programs.
• For the program's support, send the Committed value, the page file size from the Virtual memory window, your RAM size and the Windows version from winver.

If the same window shows a different code, the cause is different too. For example, our guide to error 0xc0000141 covers a program that fails at start for reasons other than memory.

How to keep error 0xc000012d from coming back

The error comes back whenever memory use meets a low limit. Keep the limit high enough and the use in check.

Frequently asked questions

What does error 0xc000012d mean?

It means Windows has run out of virtual memory. In Microsoft's NTSTATUS list, 0xC000012D is STATUS_COMMITMENT_LIMIT: Your system is low on virtual memory, and Microsoft's text asks you to increase the size of your virtual memory paging file. The commit limit is your RAM plus the page file. When running programs have reserved all of it, a new program cannot start and Windows shows The application was unable to start correctly.

How do I fix error 0xc000012d?

Open Task Manager, check Committed under Performance and Memory, and close the program that uses the most. Then open the Virtual memory window through SystemPropertiesAdvanced and tick Automatically manage paging file size for all drives, and restart. If drive C: is nearly full, free space so the page file can grow. Heavy games may need a larger custom page file. SFC and DISM come last, only when memory is clearly not the problem.

Why does the error mention WerFault.exe?

WerFault.exe is Windows Error Reporting, the process that starts when another program crashes. When memory runs out, a game or program often crashes first, and Windows then tries to start WerFault.exe to report it. With no memory left to reserve, the reporter fails too, so the window reads WerFault.exe Application Error with code 0xc000012d. The fix is the same as for any other program named in the window.

Is 0xc000012d the same on Windows 10 and Windows 11?

Yes. The code, the message and the fixes are the same on Windows 10 22H2 and Windows 11. Task Manager, the Virtual memory window and the SystemPropertiesAdvanced command work the same way on both. Windows 10 left support on 14 October 2025, so it gets no new fixes, but this error does not need one: it is about memory and page file settings on your own PC.

How big should the page file be?

For most PCs, let Windows manage it. Microsoft says a system-managed page file grows up to three times the physical memory or 4 GB, whichever is larger, and no more than one eighth of the volume size. It grows when the commit charge reaches 90 percent of the limit. A fixed size helps only when a heavy program hits the limit faster than the page file grows; then set a maximum of up to three times your RAM.

Does more RAM fix 0xc000012d?

More RAM raises the commit limit by the same amount, so it helps when the limit is reached with a working page file, free disk space and no leaking program. It does not help when a program leaks memory, because the leak fills any amount over time. Check those first. A page file costs nothing and fixes most cases; more RAM is the answer when you regularly run more than the PC can hold.

Can a game cause this error?

Yes, games are the most reported case. A user in the Microsoft Q&A thread for this code saw it in two games, after the game froze. Large games reserve a lot of memory at peaks such as loading a new map. With a browser and launchers open in the background, that peak can reach the commit limit. Close other programs and check the page file before you reinstall the game.

Will SFC, DISM or a driver update fix 0xc000012d?

Rarely. These are the usual answers in forums, but the code says memory is full, and neither tool adds memory or changes the page file. In the Microsoft Q&A thread the user tried them and the error stayed. Run them only when Task Manager shows plenty of free committed memory and the error still appears. A driver update helps only if a driver tool is the process that keeps growing in Fix 5.

What is STATUS_COMMITMENT_LIMIT?

It is the name Windows gives to the code 0xC000012D. It means a request to commit memory failed because the system commit limit, RAM plus all page files, was reached. Programs see it as a failure to reserve memory; you see it as The application was unable to start correctly. Related codes are STATUS_NO_MEMORY (0xC0000017) and STATUS_PAGEFILE_QUOTA_EXCEEDED (0xC000012C), which have the same kind of fix.