How to disk recovery which had no backup

first off stop using that drive. dont download anything to it or move files.

i personally like recuva. its small, so little drive useage incase its your main drive.
http://www.piriform.com/recuva

Ok! It is possible for you to retrieve your previous data as long as you have not rewritten it.
All you need to use is a recovery tool. If you have no idea about it, I personally recommend you to try a drive recovery freeware that has recovered all the data of my friend from a Samsung hard drive. It is worth a shot.

If you are interested, you can read more about it there: -http://blog4mark.blogspot.com/2012/11/how-to-repair-cor...

Important note: You can run this freeware more times to retrieve much more data.
You should remember to format this drive after the recovery process.
You should keep a good habit to back up your important data frequently in the future in case of similar problems.