How long have you had the new computer? I try to backup using System Restore at least weekly, and do a full hard-drive image at least monthly, as well as after any major grouping of updates that seem -- after a few days' time -- to be playing nicely.
If you have been creating Restore points, try Restoring, first to the most recent Restore point, then to succeedingly earlier ones as necessary.
Once you get this sorted, do you have a second drive (internal or external) to which you could backup operating system images, with either the Windows 7 built-in Backup, or perhaps with Macrium Reflect Free edition?