I use windows XP home, with sp2. Every time I open a folder, and especially when opening one with a lot of large files like movies, explorer.exe starts using 90-100% of the cpu.
Sometimes I hvae a similar problem with iexplore.exe, it starts using 100% of the cpu even though the page has finished loading.
I have tried to start the computer in safe mode, and run avast antivirus, adaware, and windows defender. As I write, wincleaner is running trough my system... But I just cant figure out why this is happening all the time.