WinSXS folder full of compromised files

[thx1139]

I've been fixing my friend's laptop (replacing the fan). The user experience is really slow so I've also been doing the kind of maintenance I'd do for my mum/grandmother. His AV and various other stuff has been out of date for a long time so I installed Avast! and it found a whole load of compromised .dll files in the C:/Windows/winsxs/ folder. I think it said they were rootkits or something. The default resolution is to delete. It doesn't say how many there are but it looks like hundreds. If I tell the Avast! to go ahead and delete, could this damage the system? You need to tread carefully in the Windows folder, right?

 

[whs]

Avast will make no damage. But rootkits can be a pain. Better run these too.

http://filehippo.com/download_superantispyware/

http://filehippo.com/download_malwarebytes_anti_malware/

http://filehippo.com/download_spywareblaster/