I recently installed a new hard drive. I've now upgraded to vista from XP, and when asked which drive I wanted to install on I chose the new drive. The install went fine, and everything with vista is working great. The only thing bothering me is that XP is still on the old drive, and whenever I start up the PC I'm asked whether I want to start vista or an older version of windows.
If I reformatted the old drive (c: ), would vista still run properly?
No, Vista won't boot cuz the MBR on C: will be gone. The sequence of a pc starting up is BIOS > MBR > OS.
You should've installed Vista on the same drive as XP cuz Vista is smart enough to move everything XP to a C:\Windows.old folder. Your files are intact in that folder. If you decide to ditch XP, you can delete that folder. That's it.
If you don't want to see that boot menu ever, log in as admin, start, control..., system, adv sys settings, settings under startup, uncheck "time to display os...", ok, ok.
If it's not too long since you upgraded Vista, do a clean Vista install on the old drive. Back up your files prior. Then format the new drive as storage/My Documents.
If you want to improve Vista performance, there are tools/tweaks to do.
Before you wipe everything, let me ask: Is the Vista installation new/separate? or did you upgrade XP? I understand the drives are physically separate, right?
If the Vista install is new, and the drives are seaparate, then the easiest thing to do is shut down, unplug the XP drive, and boot to your Vista DVD. When the option comes up, you can 'Repair Startup' and the master boot record will be created, updated and corrected accordingly. Leave the XP drive unplugged for a few resterts to make sure all is well. You may then reformat the old HDD as you see fit.