Looks like the active flag got damaged/shifted. It's not likely you will get the same issue again.
You will almost certainly get other little stumbles.
Best thing you can do is make regular backup images - you can restore it in a few mins if you get a prob.
There are some good free apps. for that .
It's worth installing these two freebies: Free Backup Software: Paragon Backup & Recovery Free Edition ... [EXCLUSIVE GIVEAWAY] Unlimited Free Licenses Of EASEUS Data ...
(use the rapidshare download for easeus )
You also need a decent boot disc, it will fix most things:
Put 32 bit
win 7 dvd/recovery disc in the dvd drive, rt click the dvd drive select COPY.
Rt click your HD ( e.g. C ) and PASTE.
D/L this special app. Unless you got the link already, you need to go to your user cp and enable Private messaging so I can link you to it. ( as usual rt click it >properties>unblock>apply>ok ) Unzip it , run the self extractor.
Then rt click and run as admin
Browse to the wim ( it explains where that is ).
N to add PM.
Y to add BR - browse to the launcher (it tells you where it is )
Y to add Easeus - (it tells you where to browse to.)
Y to make an iso
Y to burn the iso ( put a blank cd-r in the drive , don't format it )