Windows Bootcamp no longer bootable
Hi,
I installed windows XP onto my MacBookPro about six months ago and everything was working fine. I haven't used it for a couple months. I decided I wanted to use Windows today and when I turned on my computer and held down the alt/option key, it didn't load anything (usually it displays "MACINTOSH HD" and "BOOTCAMP"), so I had to turn on my computer again and just use the apple. I repaired all disk permissions and verified the disk on the MACINTOSH HD volume and everything is okay. I can't do anything with the BOOTCAMP volume on disk utility.
I also went into System Preferences and Startup Disk, and it does not display the Bootcamp partition as a startup volume, only Macintosh HD and "network startup"
What has gone wrong and how can I get my Windows to function again?
Thank you.
MacBook Pro (15-inch Mid 2010), Mac OS X (10.6.8)