You deleted the System boot files which were obviously on Vista. Startup Repair will write them to the Windows 7 partition
when it is marked Active then run up to 3 separate times with reboots in between.
However you can't mark a Logical partition Active which is why SIW2 advised you to first convert one to Primary.
I suggest you boot in PW CD, rightclick on Windows 7 partition, select Modify>Convert to Primary, click OK.
Then rightclick again to Modify>Set to Active, again OK.
Then click on Disk # to highlight it, from Disk tab select Rebuild MBR, Apply all steps. Reboot to see if it starts.
Rebuild MBR may preclude the need to boot the DVD or Repair CD to run
Startup Repair - Run 3 Separate Times.
Be aware that PW cannot convert to Primary if there are already more than 3 Primary in addition to the Logical partitions. You'll have to delete one or covert it to Logical.