|nipping in briefly as wanderer is helping you just now.. and best not to muddy/conphuse the waters yet... Do not write or do anything to the drive as is; certainly not to (re)format etc...|
You may find that booting with knoppix or ubunt disk will allow you to see and recover your data?
If you don't have one or other... go to their respective web-site; download an .ISO image which save to a drive; burnb to a dvd; boot up with that dvd and see if you can see/locate the data etc...? If so copy it to optical media...; verify the sopies are OK on another sytem too.
The set about resolving your initial problems?
And when you do have it all resolved... learn to regularly safeguard your data... As in copy it to optical media regularly; preferably two sets; even better to an external hard-drive too?
Incidentally how did you attempt to access the drive/partition via cmd; what did you type in there?