Windows is corrupt?
 

I've had this problem for a while now but it never bothered me. Whenever I hover on a .DAT file, explorer.exe automatically close himself giving me an error.
Also, I recently tried to run regedit.exe and it closed automatically once I try to scroll the left frame.

I have no idea what caused that but I suspect my Windows installation is corrupted?

Sounds like somethings messed up, show me the CRC32 or MD5 of your EXPLORER.EXE (use SHA-256 if you suspect fowl play). If they match up, then it's something else (like a virus), if not, then your explorer.exe is corrupted
CRC32: E67B9AC9
MD5: A0732187050030AE399B241436565E64
SHA-256: CBFBCC43B18DECA5619706FC134D25E0DCEBCD5257D0A70F57 82C42E5C2FCEC9

In any case, you can take my attachment and see if replacing explorer.exe with mine helps at all.

EDIT: Use this program to figure out the CRC32, MD5 and SHA-256 of your EXPLORER.EXE

CRC32: 90c1bd47
MD5: 98d45efddd1a67f90353be8d28ed72db

I also replaced my Explorer.exe. Regedit seems to be working now but I'm still having an error with .DAT files.