explorer.exe Issue

[.Kencs]

Please help,

My mate's PC is screwed
When he turns the PC on, he logs in (Windows XP btw) and all he gets is his desktop.

Windows cannot find explorer.exe when I go to New Task in Task Manager and type explorer.exe

When I type in C: to try and access the C: Drive I get the 'Open With...' dialog box.

I have ran sfc /scannow with an XP CD and nothing has changed since running that.

Please help as I am running out of ideas.
I can load firefox and a few other stuff via 'New Task'...

 

[asim18]

Maybe some malware has messed everything up, deleted explorer.exe, etc..

Best thing to do would be to use a utility boot cd (eg. hiren's boot cd) to back up all your important files, then reinstall Windows.