chandler sörenson

i am attempting to install advanced server from professional. i have a
300GB disk that is partitioned: C:20GB and D:10GB. C: is where i have
professional installed and i would like to install advanced server on D:.
when i run the setup and the computer reboots i get this error message,
which i have found to occur in different situations, but not during advanced
server setup:

stop 0x0000007b (0xf2463848, 0xc0000034, 0x00000000, 0x00000000)
inaccessible_boot_device

i did chkdsk /f, like it said, on both drives and i am still getting the
error. i read some things about the debugger not being active at this point
in the startup procedure, and that might be the cause? i didn't quite
understand how to fix the problem though. any insight would be appreciated.
thanks.