Toshiba external hard drive not recognised by desktop with Vista

[balliali]

Advice appreciated, please and thanks.
My desktop computer has stopped recognising my Toshiba external hard drive. When I go to save (e.g. Word document), I cannot see the (F) drive in My Computer. The external drive is connected properly, and the blue light is on. This is a recent problem, as up to the last week I had no problems, and I have a lot of data stored on this drive.
Advice appreciated on what the problem might be, and a solution for it, please... don't want to lose any data from computer, and would like to be able to access stuff already stored

[Old_Geezer]

If it is external you can try it on a different PC to isolate whether the problem is with the PC or the drive.

Another port of call is to look at it in the Device Manager, see if it shows a problem.

[stoofur]

Are there any other drives listed? Sometimes Windows will allocate a different drive letter.

[mickrog]

if all else fails restore pc to a date when you know the external hd was working

[rojash]

Unless you've specifically told WIndows to allocate a particular drive letter, the drive letter can change according to the order in which you connect stuff.

E.g
Plug in a hard disk, it takes letter F
Plug in another (or a USB stick) It takes letter G

Unplug them both, plug in the USB stick, it takes letter F, connect HDD it is now G.
Unplug USB stick, F disappears.

Check that the HDD hasn't been assigned a different letter.

[balliali]

Thank you all very much for your input. I rebooted my computer with the drive plugged in etc, and a message came up telling me a driver for an unknown device was successfully installed. However, I still cannot locate or save stuff onto Toshiba, will keep trying, thanks again.

[balliali]

Got a solution here....http://tim.mackey.ie/VistaDriverProbl
emsFormacUSBHardDrive.aspx

My F drive now becomes my G drive, but anyway all is not lost, thanks for all help.

[Old_Geezer]

You can change drive letters in drive manager.