Vista 64 bit OS doesn't boot ....comes with GRUB and stucks

[sdsu]

Hi folks,
I am kind of new to linux .. i have a gateway laptop with 64 bit vista on it... i have WD HDD 160 gb and i though of installing centos onto ext HDD by disabling the internal hdd and i even tested it with this setting in order to make sure ...i don't mess up with the internal hdd and it didn't boot and said it has no os installed making me confirm that the internal hdd will not be messed up !
and installation went fine and then when reboot it with the ext hdd ........ just came up with the grub console and did nothing and kept a side... and removed that ext hdd as i'm not very comfy with grub .....infact i don;t much how to deal with it !
So when i reboot my laptop with internal hdd enabled .....it just came up with the GRUB and does nothing ..not even a error ......and i'm now not able to get my vista 64 bit boot .....
Guys can some one help me out with this.... i have all my critical data in it ....and i have been breaking my head .....with not much luck ...!

I tried the windows XP recovery console .... but it is not able to run the fixboot command propably ....since it has vista 64 bit installed on it....and xp can't read it .......and i only have gateway recover drive which is burned to cd.... but it has only one option of recovery to factory setting .... but no option to repair or something ??????????

Plzzzzzzz guys help me out with this.... this is really imp.... i have all my research work over there...... and now i'm totally messed ......i don;t know what to do??????

[Expertz]

From the information you have given I would guess Grub is having issues reading the RAID array. What type is it? If you knew the raid chipset you could try to google something like: raid grub and the chipset name and see where that takes you.

[WMBrown]

Try doing system restore in Safe Mode.

... Windows Vista Safe mode, as the computer is booting tapping "F8 Key" which should bring up the "Windows Advanced Options Menu"

... Use your arrow keys to move to "Safe Mode" [PRESS ENTER]