If no infection is found, can you download and burn to CD free Partition Wizard and take a good camera snap of it's drive map? Post it back using paper clip in Reply box.
If not, follow the steps I gave in my first post to make sure either 100mb SysReserved partition (if you have it) or Windows 7 partition itself is marked Active, then run Startup Repair up to 3 separate times.
Are you using the DVD or Repair CD to do your repairs? System Repair Disc - Create