You can download a repair disc I made. https://skydrive.live.com/#cid=B0A22...89320E3247!345
The file to d/l is called REP.7z.
Rt click it >properties>unblock>Apply>OK
It is a .7z file , so you need the free program 7-zip to unzip it. http://www.7-zip.org/
That will give an .iso file, which you burn to cd as an image.
If you don't have an image burner, use this from the lovely people at Terrabyte: burncdcc.zip
Boot up the cd on the sick machine.
Drive letters will look different from there - don't worry, that is normal.
Find your windows drive letter and your active partition drive letter. ( You can fire up partition wizard to see which is the active partition - while you are there , check if your Windows partition is shown as Primary, or a Logical partition. )
Close partition wizard and open NT6Repair .
Under Auto Boot Repair , select your Windows partition and your active partition letters, and click Apply.
See if that does it.
If that doesn't do it - try it again - this time (IF your windows partition is a Primary ) , mark it Active , and then select your windows partition in both dropdowns.
( If that doesn't help, we can replace the registry hives from backups )