I made partition by using Disc manager, and accidentally marked C drive active. After restarting an error message is showing. I cant get into DOS command prompt , even by hitting F8. I used my recovery disc, but it tells me "No OS found!" . My laptop ACER has come with a pre-installed Windows 7 home premium 64bit. Can i solve this problem without formatting C drive, bcz i didnt make back up of many of my important documents stored in C drive. Plz help