Hardware setup: one SSD disk (C: - formatted as NTFS) and one big (2 TB) hard disk partitioned in two same sized NTFS parts(D: and E:)
System: Windows 7 64bit, Enterprise Edition.

Long story short: while playing a game the computer freezed. After reboot I no longer see the partition E: (which is where the game was installed).

I opened Disk Management and the partition is not there either.
I guess the MBR got corrupted but I'm not sure on how to proceed.

Any ideas?

If it does use the GUID partition table (GPT) There should be an MBR backup. You'll want to check with parted or gparted in Linux and see if it detects any GPT information. Otherwise, your remaining two options are probably these: see if you can scrounge up some software that will attempt to algorithmically reconstruct your MBR based on a search for filesystem information, or use data recovery software such as GetDataBack which will allow you to access some files amidst corruption of the filesystem and MBR.

Thanks all for the suggestions!
Yesterday night I tried to proceed as suggested but nothing useful came out. Discouraged, I went to sleep.

While in bed it came to me that maybe I was remembering wrong; maybe I actually had 3 distinct hard drives. This morning I opened the case and I found out that was the case (dumb me!).

As a last ditch effort i simply plugged more firmly the SATA connectors, I started the system and, VOILA', Windows was seeing the missing disk!

Two lessons:
1) don't trust your memory
2) Sometimes it's enough to make sure the plugs are well set

Thanks!

UNHAPPY UPDATE:
The disk once again disappeared
Do you think it's a connection problem or is the disk dying?

You could also try a new SATA cable... Or IDE if it's IDE. Especially if it's IDE. Er.. You already said it's SATA. Herp.

I don't think that would make sense for a missing partition. If he had have suggested an entire drive disappeared I'm sure you or somebody would have thought of the cables. We were under the impression that only a single partition from a drive was missing, but that other partitions on the drive were working fine.

We did take his word, I think one of us probably should have at least asked if the drive was showing up at all. Just because it's one potential problem.

I was not, I assumed that the entire mbr was gone. It's only like one (old size) sector. 512 bytes is not hard to corrupt. Especially with newer drives with SMR and 4k sectors

When he first made the post, he assumed that he only had two drives total in his system. It wasn't until he checked the actual hardware that he noticed it was three drives.

I know that on my system, I have one drive with two partitions on it.

That's not something to apologize for. In tech., those kinds of things are what most often leads to a solution. You begin trying to explain something that doesn't make sense, and then an idea pops into your mind: something doesn't fit! And then you realize, you've had a bad assumption all along and the fix is actually simple. Often the person asking is the person that comes up with the solution because they have the most knowledge of the actual problem context, but they might not have been able to reach that conclusion if not for walking others, and therefore themselves, through the problem.

Gull is correct here. If you can, and care a lot about the data make a copy of it before letting the OS mount it, or running a chkdsk or scandisk. All three things will modify the filesystem, and potentially make any corruption worse.

FMC: That's a good then. J'aime mieux ça ;-)