Spyware, viruses, & security : WinMe directory-overwritten with nonsence

WinMe directory-overwritten with nonsence

In the spring 2006 my son was watching a DVD and it stated to actup-video got choppy and just refused to continue to play. I thought an update of some sort was downloading so I checked-no download. I restarted the computer,running Windows ME with Mcafee Virus Scan and Zonealarm for a firewall, an error message came up:it couldn't start Windows/couldn't find the OS! So I put in a boot disk and restarted the computer to look at the Windows Dir. The WinMe Dir had been overwritten in the middle with nonsense. The begining and the end of the Dir was still there. But enough that WinMe was toast! Couldn't run McAfee scan to see what caused the WinMe Dir to be over written with nonsense. Atleast it wasn't a boot sector virus since I was able to reformat the harddrive and reinstall WinME. It has not come back in. In July I installed WinXP. I wonder what it was? trojan horse maybe? Whatever it was it got passed McAfee's shield and Zonealarm firewall which I kept up to date along with WinME!