Boot into Win7 DVD System Recovery Options
or Win7 System Repair Disk
to Mark Win7 Partition Active.
Then run Startup Repair - Run 3 Separate Times
until Win7 starts and holds the System Active flags.
Be aware that sometimes GRUB can corrupt Win7 beyond repair when on the same HD. I would delete it completely and then for any future Linux Dual Boots use separate HD's booted only via BIOS, or Dual Boot Ubuntu with EasyBCD - NeoSmart Technologies Wiki