A few days ago I was installing some software and power went down. When I rebooted, the partition to which the software was installed was not accessible. Disk manager shows that it's there, but doesn't show type, if it's healthy and gives me an error when trying to read its properties.

The problem seems to be common after power loss, people recommend solving it by assigning a letter to the partition via DiskPart utility, but partition isn't listed in my case.

I can access that partition with bootable OSs (like bootable Ubuntu or winXP) and all the files are there, but another installation of Windows 7 gives me the same results as the original.

I could just copy all data to another disk if there was enough space, but unfortunately the size of partition I'm having problems with is 1.1TB.

How do I regain access to the partition in my original Windows 7 installation without losing any data?