Assuming you havent Formatted .(re your other thread )
Then its possible to enter Dos command prompt (hit F8 before windows loads)takes a little practice))at bootup and at the resulting command prompt type scanreg /restore choose a date you know was a satisfactory bootup . and follow prompts. That should return you to a point when every thing worked well, There is a downside to that though . It also eliminates any software /hardware drivers added since the date chosen.. But at least you dont have to reinstal every thing..