Without a boot partition - you will not be able to boot. Somewhat self explanitory.
If you have data on the hard disk that you need to recover, your best bet is to take out the drive and to use a second computer to recover the data. There are some nice external enclosures you could use - such as:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817153071
Once you have your data safely stored someplace other than your hard drive you can work on fixing the boot partition.
You could always re-install windows and it will format and create the boot partition.
OR
You could follow these instructions which use the 'BOOTREC' command:
http://pcsupport.about.com/od/fixtheproblem/ht/new-partition-boot-sector-windows.htm
Good luck.