How can I access my windows files?

I had a virus and it would not let me access my windows files and wreaked havoc on my comp. I finally removed all of it but I still can't access my files. When I go to my computer/c:, there is a file called "Bootsect.bak". However, if I do a file scan, all of my old files show up so I know they are still there plus the C: drive is almost full to the same point so I know it is there. How do I unload them from the .BAK file?