>>1) Is there a way to verify if a file from Microsoft is authentic or has been tampered with?
>>2) Is there a way to do that verification under program control?
>
>What kind of file?

An executable file. For example, I found a file in \windows\system32 that had that day's date, which made me very suspicious. It would be good if there was a way to check with MS itself if that file is legitimate. It would be best if there was a way to then repair the file. Sounds like a good service for Windows Live.

Thanks for the response.

Alex