You need to make sure the infection is out. Download and write to flash stick Microsoft Standalone System Sweeper
, boot it to do a full scan without System Files running.
Now you need to repair System Files. Write the Windows 7 installation DVD to flash stick using UltraISO trial version: On File tab select Open DVD or ISO, on Bootable tab select Write Disk Image, Format, Write. Boot stick under USB, Removable or HD's on one-time BIOS boot menu, select Repair console on 2nd screen, accept any offered repair. Then boot back in click through to Recovery Tools list, open a Command Line to run SFC -SCANNOW Run in Command Prompt at Boot
If you can't find a Windows 7 installation DVD/ISO to write to stick then you'll need to burn a System Repair Disk
and try to get it to boot correctly by reinstalling your CD drive, cleaning it, borrowing or buying another, or writing disk ISO to flash stick using Win2Flash.
If you can't retrieve your files, you can copy them out using DVD/Repair CD this way: Copy & Paste - in Windows Recovery Console
Then run Factory Recovery using the link Britton gave you above, Recovery Disks you made or order, or a Windows 7 installation DVD to clean reinstall following these steps to get it perfect: Reinstalling Windows 7
Report back your progress for further steps.