PC FREEZES FOR 15-20 MINUTES AFTER WINDOWS WELCOME SCREEN

hello,

i’m working on an HP Media Center PC M7680N.

on bootup, it makes it through the HP screen, and then the Windows XP screen and then it just hangs there with a blank screen for 15-20 minutes before finally launching into windows. once in windows it works great – very fast.

things i’ve already tried:

– safe mode (same thing happens).
– reset bios to defaults.
– ran chkdsk /r from windows cmd prompt
– ran sfc /scannow (don’t have the xp pro cd which it wants, i only have an xp home cd.
– removed all viruses, adware and spyware.

since i don’t have the o/s cd for this computer, i can’t just re-install the o/s. does anyone have any ideas on how i might be able to fix this problem?