I installed today a Win XP on the second partition of a Dell Inspiron laptop - on the C: partition was installed Win7. During the setup there was created a special system reserved partion - C:, and the original win7 system partition was renamed as D. So, of course, it wont boot. XP installed on G: drive, no problems here. I need on the laptop both XP and Windows 7, how can i recover Win 7 to a fully functional state, and still keeping XP?... I guess MBR went pretty f*d up...
Dude, this is a hella easy fix lol. I did the same thing once and all I had to do was insert my win7 install disk and select "Repair" it will find some issues with either the BCD or the actual boot system during the autofix process. Let it fix that issue and wala, it works again. The best advice I would give you to prevent this issue coming from someone who dual boots xp and win7 is to always install the older OS first. If you installed XP then win7 you would not have this problem dude. That is the best advice I could give you for the future lol