i did this when i booted with the MSDOS disk..

1st: command: fdisk /mbr and it worked cause there was no error msg
2nd: i checked the disk out a bit with command dir and saw there was a fdisk.exe so i launched it and it took me to a menu with a few options and information, yes it also had some stuff with partitions and activating something, cant remember now (im at school right now)

i never had such a problem so im thinking is there something else i can get that would make this easier to fix, like a partition magic boot version or would the xp setup boot (6 disks) help me?...also i did play around with those active partitions in DOS boot so i guess i would have to get that back to normal somehow...it all looks messed up though, but i think ill do that first and then go to other boot disks or something...and if that dont go ill just take my disks out and back it up onto my friend's computer and then hope that my recovery disks would get it back to normal (speaking of my primary drive)