Recovering Lost Data
Immediately check your Trash / Recycle Bin
Hopefully, this will be all that you need. But if the file is not there, you may need to do:
Is the document that was deleted or destroyed on the same drive as your Windows folder? If so, there is a very high chance that the document has already been overwritten, and cannot be recovered.
If you have just deleted a file within the last few seconds, the best thing you can do is pull the plug on the computer. Don't shut it down from the start menu; don't continue using the computer.
Once powered down, take the hard drive to another computer (this may require extra tools and cables), and use a data recovery program to restore the deleted file.
Your data should be on a different drive
Your hard drive should be divided into two sections (or "partitions") - a "C:" drive and a "D:" drive -- the operating system, and any programs you have installed should be on the C:\ drive, and everything else -- your documents, email, etc should be on your data drive (D:\)
The big name brands are only interested in selling units, they are not interested in you, or your data, and so do not partition your hard drive storage correctly... so this is normally something you will need to do yourself.