Not able to copy from USB hard drive

As i have mentioned in my title i am not able to copy my data from (160 GB)USB drive.
Whenever i try to do it some of the files get copyed and it gets haulted for sometime. But the system is not haulted only the copying process is haulted.
Can any one give me some procedure where i can get my data back and that data is very important to me.I would highly appreciate any solution.

I guess your hard disk is on the merge to get corrupted or has corrupt.Try to get only the very important files.

To get the files follow the steps:-

go Start -> run -> type "cmd" (no quotes) -> press enter -> type "chkdsk x:"

Where "x:" is the driev name of your usb drive.It will find if there are any errors.