Did you run Startup Repair at least 3 times with reboots from DVD or Repair CD as stated, while Win7 partition is marked Active?
You may need to check for infection. Download, burn to CD or write to flash stick, boot and run a full scan with Microsoft Standalone System Sweeper
. Then run the Repairs again.
Boot free Partition Wizard bootable CD
to see if Win7 partition is marked Active and what flags it currently holds, then click on Disk number to highlight it, from Disk tab select Rebuild MBR which will sometimes preclude the need to run Repairs.