help!bootmgr is missing....

I unknowingly set my partition drive as active.....now i cant boot.i am using windows 7 home premium.i dont know what to do...also dont want to loose datA on my drives.

Try this:
Startup Repair
Note: You may need to do startup repair 3 to 4 times.
Startup Repair - Run 3 Separate Times

System Repair Disc - Create
System Recovery Options
System Restore

You will need to set Win7 or it's 100mb System Rserved boot partition (if you have it) Active before running the Repairs.

Partition - Mark as Active using Diskpart from System Recovery Options.

Or use free Partition Wizard bootable CD to have a picture of what you're doing. If you use PW CD once you Modify>Set to Active 100mb or Win7 partitions, then click on to highlight the Win7 HD and from the Disk tab select Rebuild MBR which may make the REpairs unnecessary.