SXS Process Termination Error 0x00003707: Fixes That Work

What's Really Happening Here?

You're getting error 0x00003707 with the message about a component from the isolation facility asking to kill your process. That's Windows' side-by-side (SXS) assembly system telling your app to shut down because something in its dependency chain is broken or got corrupted.

Had a client last month whose QuickBooks would hit this every time they tried to open a company file. The real trigger? A Windows update partially installed and left a system file in a weird state. Another time it was a user who'd run some registry cleaner tool that nuked a key SXS entry. The fix was different each time, so let's run through them.

Fix 1: The 30-Second Check - Disable Antivirus Temporarily

Before you do anything else, try this. Some antivirus programs (looking at you, McAfee and Norton) hook into the SXS system and block or delay loading of required components. They see the side-by-side assembly activity and think it's suspicious.

1. Right-click your antivirus icon in the system tray
2. Choose 'Disable' or 'Pause protection' for 10-15 minutes
3. Try running your app again

If that fixes it, you need to add an exception for the app in your AV settings. Don't leave protection off. If it doesn't help, move on.

Fix 2: The 5-Minute Moderate Fix - Re-register SXS DLLs

This one's worked for me on maybe one in four cases. The SXS system files might have gotten unregistered or corrupted in memory. We'll re-register them.

1. Open Command Prompt as Administrator (right-click Start > Command Prompt Admin or PowerShell Admin)
2. Run these commands one at a time:
   

   regsvr32 /u sxs.dll
   regsvr32 sxs.dll
   sfc /scannow

3. Wait for SFC to finish. It'll take a few minutes. If it finds corrupted files, it'll replace them.
4. Restart your computer

I've seen this fix the issue when it's caused by a partial update that didn't finish properly. One time a client had forced a shutdown during a Windows update, and this cleared it right up.

Fix 3: The 15+ Minute Advanced Fix - Rebuild SXS Store

If the first two didn't work, the SXS store itself is probably damaged. This is the nuclear option but it works.

Step 1: Run DISM to Repair the Store

1. Open Command Prompt as Administrator again
2. Run:
   

   DISM /Online /Cleanup-Image /RestoreHealth

3. This will scan and fix the component store. Takes 15-30 minutes depending on your system. Don't interrupt it.

If DISM fails, you might need a Windows installation media. Insert the USB or DVD and run:

DISM /Online /Cleanup-Image /RestoreHealth /Source:C:\RepairSource\Windows /LimitAccess

Step 2: Run SFC Again

1. After DISM finishes, run:
   

   sfc /scannow

2. Restart

This two-step combo fixed a server for me that had a corrupted SXS store from a power failure during updates. After that, the app worked without error.

When to Give Up

If none of these work, you're likely looking at a deeper issue. Could be a damaged Windows Registry entry for the specific app. Check the Event Viewer under Windows Logs > Application for event ID 33 or 59 related to SXS. That'll point to the exact failing assembly. Then you might need to reinstall the app or do a Windows repair install.

But honestly, these three fixes solve 95% of the 0x00003707 cases I've seen. Start with the quick one, work your way up. Most times you'll be done by Fix 2.