Hi everyone, So im Running Windows Vista Home Premium on my laptop and leant it to a mate to borrow while I was away.. when I got home i went to turn it on and it completed the POST test but then came up with a message saying : the file is possibly corrupt. The file header checksum does not match the computed checkcum. - so im guessing the laptops not likiing the OS software. He swears he just turned it off normally the last time he used it but im not entirely sure bout that....to me it sounds like a boot/companion virus. Anyways I went in and did some short and long scanning of the hardware through the boot system menu on startup and everything checks out. and is ok. I've got the WinVis:HP disc but can't boot from disc.. If i could Format the harddrive I'd just re-install WinVis but im having a bit of trouble formatting. Can anyone give me some pointers on what do do and how to go about it. Thanks.