please help me

Hello. I have installed new windows 7,on my previous windows 7. Till that, i have saved my important files in Local disc D. Windows is installed on local disc C.But previous windows version moved moved to D disk. And my files, that were in D disk, have lost.What can I do for moving back my files, which are very important for me....??please, help me,if you can.
Thanks Beforehand

Lets see if I can sum this up.

Windows 7 was on partition 1.
You moved your data to partition 2.
Then you mistakenly installed Windows 7 to partition 2.
Now Windows 7 boots to partition 2 thus switching the drive letters.

Question: Did you format the partition before you installed Windows 7?
If so then your data is lost forever.

If you did not format then your data will still be available. You only need to search partition 2 for your data which is now labeled as C:\.

Yes, Windows 7 was on partition 1. then i moved my data to partition 2.then format partition 1, and then installed windows in partition 1. i can't do anything ?

it isn't right?

If you now have Windows 7 installed on two partitions, then you formated and installed to the wrong partition. Since you say you did format, there is nothing you can do to get your data back.

I hate telling you this:
Once you installed Windows 7 over the top of your data, there is no retrieving the data. You can retrieve data from a format but not once it has been over written.

Are you absolutely sure that the data isn't on drive D? When you install to Drive C: it would setup new libraries on C: but there could still be stuff on D:. Are you just looking in favorites or have you actually gone to D: and the drive is completely empty?

But, as Clifford said, if you did accidentally install over-top your data then it is gone.

This is another prime example of why users should invest in an external hard drive, in order to save their data to it.

Even an extra internal hard drive will suffice as long as they're aware of which drive it is so they don't accidentally install on OS onto it.