First, a small trick. If a disk drive doesn't open automatically, get a paperclip and on the drive door you'll find a tiny hole (about the size of the paperclip tip). Insert the paperclip and push a bit and it should open the drive enough for you to manually pull it the rest of the way.
Well, i have done this before, it works fine no doubt, but its kind of obnoxious trying to find a paperclip every time i want to open the drive door. That and it works just fine intermittently.
I can't think of anything with Vista that would cause that, so I'm inclined to think either there's a problem with the drive (some sort of internal hardware problem that most likely is cheaper to replace the drive than try to repair) or with the drivers for the drive. Let's check out the drivers.
Go to Device Manager by going to start / search box and type device manager and enter and then double-click on the program icon that appears. Check each device for a red x, yellow ! or white ?. These identify devices with problems (probably drivers, but also conflicts or something else). Click on each for further details and troubleshooting tips. If you need to get drivers (and you should get drivers, firmware and/or software for the disk drive at least and any others you have time to do - they may help in ways beyond just resolving this problem), do so from the computer vendor or device manufacturer (NOT from Microsoft Updates). Proceed as follows to get the drivers: http://pcsupport.about.com/od/driverssupport/ht/driverdlmfgr.htm. Once you have the drivers, you can install them through Device Manager as follows: http://www.vistax64.com/tutorials/193584-device-manager-install-driver.html.
Then reboot and see if that helps.
Well i checked my Drivers and everything is up to date, the only thing i have is an Exclamation point on my Ethernet thing..
If that doesn't work, try a clean boot http://support.microsoft.com/kb/929135. If the problem goes away then it's just a matter of tracking down the culprit causing the problem. Follow the procedures in the article. Once found, delete, remove, deactivate, or uninstall it. Once done be sure to reset Vista back to normal status as explained in the procedures. If the problem occurs in clean mode then just restore the system to normal status and reboot - this solution is not going to work.
Boot into Safe mode with networking and see if the problem occurs there. Either result helps us narrow down the search for the cause.
If none of that worked, I'm afraid that the most likely cause is some internal hardware problem with the drive and it needs to be either serviced or replaced. If you have another drive on another computer, try swapping them and see if the problem stays with the computer or moves with the drive. That should confirm the source of the problem. If it turns out to be the computer (and that will surprise me greatly if the above didn't work), post back and we'll try some other options to track down the cause and resolve it.
I hope this helps.
Good luck!