Uh, it's hidden. Remember playing with any boot/partition managers?
I'd suggest knoppix or ultimatebootcd (both have loads of tools) but <a href="http://mbrwizard.tripod.com/">MBRWiz</a> is smaller.
1) <a href="http://mbrwizard.tripod.com/MBRWiz.zip">Download MBRWizard</a>
2) Extract somewhere
3) run cmd, and cd to the folder from step 2.
4) still in cmd, "mbrwiz /list"
5) still in cmd, "mbrwiz /unhide=(partition number from last step)