[unicorn]

A viiri.
Scan your system, reboot into safe mode and run this regfile:

Code:

REGEDIT4

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System] "DisableRegistryTools"=dword:00000000 

[HKEY_LOCAL_MACHINE\Software\CLASSES\exefile\shell\open\command] @="\"%1\" %*" 

[HKEY_LOCAL_MACHINE\Software\CLASSES\batfile\shell\open\command] @="\"%1\" %*" 

[HKEY_LOCAL_MACHINE\Software\CLASSES\comfile\shell\open\command] @="\"%1\" %*" 

[HKEY_LOCAL_MACHINE\Software\CLASSES\piffile\shell\open\command] @="\"%1\" %*" 

[HKEY_LOCAL_MACHINE\Software\CLASSES\scrfile\shell\open\command] @="\"%1\" %*"

Just made some quick thinking, not sure this will be the cure (on the other hand it won't make any harm).