Explorer.exe crashes when joining/creating homegroup

Hi,

I get the following error if I try to create a homegroup or try to join an existing homegroup:
"
Problem signature:
Problem Event Name: APPCRASH
Application Name: Explorer.EXE
Application Version: 6.1.7601.23537
Application Timestamp: 57c44efe
Fault Module Name: xwtpw32.dll
Fault Module Version: 6.1.7600.16385
Fault Module Timestamp: 4a5be0a9
Exception Code: c0000005
Exception Offset: 0000000000010bff
OS Version: 6.1.7601.2.1.0.256.48
Locale ID: 1033
Additional Information 1: c929
Additional Information 2: c929297764452c8aa6fd88cc0f8da414
Additional Information 3: d4bc
Additional Information 4: d4bcc9f6fd24cee387d707edb20e9e24

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"

The computer was previously in a homegroup and functioned properly. I have tried using the troubleshooter but to no avail. The problem started after I changed the router, but other computers of the same build connected to the same router have no such issues.

Thanks for any help!

Right click on command prompt and chose run as administrator.
When it comes up type in with out the quotes "sfc /scannow" .This will rebuild your system files in case they got corrupted. Keep in mind though that any customization's you made to any system files will be lost and need to be redone.

Thanks for the reply.

I tried it but unfortunately it still does not work. It said some files were unfixable and created a massive log file. I tried to create a homegroup afterwards but the results were the same. Anything else i can do?