Try StartUp Repair from a Windows Installation or Repair Disk which often workd when
it does not from Recovery or a Recovery Disk. If needed you can make a Repair Disk
on any computer with a CD burner running XP, Vista, or Windows 7 since there are no
files used from the Host computer.
You can try some of these in Safe Mode - repeatedly tap F8 as you boot.
If you do not have a Windows 7 disk you can borrow a friends as they are not copy
protected. Your System maker will also sell the physical DVD cheap since you already
own Windows. Also you can make a repair disk on another computer.
Try Startup Repair - (If at ANY point you gain some but not full access to Windows come
back and try Startup Repair again.)