Help my D drive had disappeared!

[Lavendersbluedillydilly1969]

Had all my photos and videos backed up on a partitioned d drive on my computer as well as some very disorganised DVDs.
Went to look at it this morning and the D drive is nowhere to be seen. If I look on My Computer it shows the C drive and the F drive only. How can it have just disappeared. It's never normally used and is only a backup?
Please help me, if I have to reload the DVDs etc it will all be such a mess and there are loads of duplicates etc.

A few questions first Is it a partition on the same hard drive or a separate hard drive? Is there any strange noises? There is a possibility that the hd may be corrupt.

It is a partition on the same hard drive. No funny noises and windows security says all ok, it's just disappeared.

Try clicking on "C" drive to see if the "D" drive has been switched off, do this by right clicking on "C" drive properties. you can access "C" drive by clicking on "start" then "my computer".

As Bureni says it may have been turned off or security settings may have blocked it.