I was hoping you had made backups of your OS and data partitions before this happened. If not, probably the only real solution is a fresh reinstall of Windows, and if you're using bitlocker - going forward, keep a paper log of your usernames, passwords, etc. in a locked drawer.
well-balanced, well-configured mult-layered defense is best
From MS-DOS 3.3, MS-DOS 6.22, from Windows 3.1 to WFW 3.11 to Windows 95-98SE, now to Windows 7 Pro.
Security for now: Windows 7 Firewall, Emsisoft AM, MSE [scan-only], SpywareBlaster, Ruiware/BillP combine