i had a windows vista,i made a partition HDD, and installed a windows xp on it. I didnt format anything on the other HDDs, and now i cant connect to the windows vista. Anyone help?

Is this related to your other post about 2 Windows that's located here: http://www.bleepingcomputer.com/forums/topic155790.html

nope, it doesnt. The 2 vista i got is in the C: and D:, but i can choose which which to go in. But after i installed the windows xp, it doesnt let me connect to these two

When you installed Windows XP it overwrote the Vista Boot Loader. I'd suggest running Startup Repair from your Vista installation DVD: http://www.bleepingcomputer.com/tutorials/tutorial148.html

What if i dont have the vista installation dvd?

How did you install the second copy of Vista?

You can get a copy of the Startup Repair ISO from here: http://www.thecomputerparamedic.com/files/rc.iso
Then insert it into your DVD tray and boot from it to run Startup Repair.

i downloaded that and burned it on a cd. But it doesnt work when i run it in boot menu.

Did you burn the ISO using an ISO burner? If not, it won't be bootable. If you don't have an ISO burner, I'd recommend this free addon: http://isorecorder.alexfeinman.com/Vista.htm

This is what happened when i boot the cd

A problem has been detected ..................

Technical information:
STOP: 0x0000007E (0xc0000005, 0xF74E0BF, 0xF78DA208, 0xF78D9F08)

PCI.SYS- address F748E0BF base at F7487000 Datestamp 3b7d855c