Internal Hard Drive Logical Partition now missing...

I have been searching for days around the net for a way to resolve this and haven't seen anything that can help me thus far, so hopefully one of you kind people may be able to help.....

I had a bit of a hard drive issue a few days ago.... my D: Drive disappeared... it's a partition on my Hard drive which I just use for music/photos etc.... it was there on Monday..... I did a full (Windows) back up (thank God) on Monday evening as I was planning on installing some software a few days later.....

I have an Acer 8920G running Windows 7.

Then on Tuesday my Acer proprietary media player needed lots of updates performed to it (it was the first time I had actually needed to play a Blu Ray disc in my laptop for over a year so I guess all the updates were successive).

When I rebooted for the final time, I noticed my D: drive was gone. Now, the thing is, I cannot be sure that the updates to the Acer Media Player was the issue but that is the only change that was made to the laptop since the back up.

I tried restoring my system back to a time point from Monday (when I knew the D: Drive was present)... still didn't come back. I then looked on Disk Management.... the only partition that is showing up with a letter is the C: drive.... there are three other partitions... the recovery one, another small one (not sure what that is) and then the 140GB one that says "Healthy. OME partition" or something like that.... I cannot assign a letter to it by right clicking on it as that just brings up a "Help" tab....

I then tried re-installing Windows 7..... that didn't bring it back either..... the laptop works perfectly fine from C:... the OS and everything is fine.... it's just D; seems to have spirited away.

I looked on Google and everything points towards data recovery which I don't need (as I have a back up) but can't really see anyway to recover the partition itself......

If push comes to shove, I can live without the internal partition and just restore my former D: drive contents to an external hard drive and point iTunes to that and make sure all my music/video/photo files point there instead.... actually, it's probably somewhat safer.... it's just annoying me that I cannot figure out how to bring D: back from the dead.

Thank GOD I did a full back up. However, is there anyway I can "restore" the partition so that it shows up again? It looks as if it's almost unmounted.... however, I cannot find an easy way (or one I can understand) to "remount" it....

Again, as I say, it's easy enough for me to leave the external drive plugged in and use that as my media drive to store music etc. It's just bugging me now as to how to restore my former D drive.

Any tips most welcome.....

Here's a screen shot.....