Hi there,
If you do not have any recovery disks at all but you DO have a Recovery Partition that is intact as You indicated in an earlier post then this is a method to install your OS again. Have a Look here:
http://www.briteccomputers.co.uk/forum/tutorials-and-how-to/reinstall-from-recovery-partition/msg1826/#msg1826
Essentially, you need to make you Recovery Partition the Active Partition and to do this you need access to the Command Prompt so that you can use the Diskpart Utility to carry out this procedure and your best bet to achieve this is to slave your HDD on a working PC, when you have completed this part switch the HDD back into the original PC then boot directly to the Recovery Partition and recover your OS. When done, run Diskpart again and deactivate the Recovery Partition and your OS partition will be the Active Partition.
For future reference you can get a Win 7 system recovery disk here:
http://neosmart.net/blog/2009/windows-7-system-repair-discs/Cheers,HTH,
ticker
ticker