Microsoft can't and won't ever contact you this is the typical call and get s--- deal had a friend tell me this same story and paid 400 bucks to have them the people on the 800 number "fix" his computer and also as a bonus steal all his data , bank info etc. I couldn't keep my mouth from falling open as he told me what he did.. he's no dummy but I couldn't believe he believed the story they sold him !
Fix ? Malware bites maybe or worst case and best to make sure wipe the computer and restore your backup disk and then restore your data . It'll take a couple hours and your sure it's clean . Or spend a few days with fixes ? Your choice of course . You do have your data / photos backed up on a separate drive somewhere right ?