9:09 am MDT and CR, it's not something I can explain. Your Techie person should have checked to make sure your Windows log-in was reset to a default, many virus and malware programs go in and change this to lock you out. When it's at the default, the first time you log in it will ask you to set the password, and you're good to go.
Otherwise, they may have to back up all your data, re-format and re-partition the hard drive to wipe it totally clean (trust me, one of the only secure ways to completely eradicate a virus or malware) and then re-install all your software from scratch, BUT NOT FROM THE BACKUP OF YOUR DISK. That backup will, of course, house the virus. If you have your original software CD's, so much the better to install them from there and then download all the appropriate patches/upgrades to date. Any technician worth his salt should be able to restore your computer to a working state . . . unless the virus was one of the worm or Trojan types, in which case it will have "eaten the brain" of your hard drive and you may be facing replacing the hard drive itself.
(This is one of the reasons I set my home computer up as a "managed desktop". Unless I'm logged in as the Admin (which I rarely do unless I need to install a software patch), no one and nothing can write to my C: drive and destroy my root software installation. I also have a D-link router with both a hardware and software Firewall, it was the best $60 bucks I ever spent, LOLOL and I hear they're even cheaper now.)
Hope you can get your system back up and running soon.