Files deleted but cannot be seen in the recycle bin can I rescue them and how??

You need to purchase a software that recovers it. I've successfully recovered important deleted files from a disgruntled employee's PC.
http://www.recover4all.com/

If you really want the files back, stop using the system RIGHT NOW.  Whenever you use it you risk writing over the old data (which, if you are lucky, is still there, just not easily accessible).  Simply by booting Windows you risk overwriting the data by virtue of Windows using the hard disk to store temp files.

So, shut down, then use another PC to look for some software like JJ2 has suggested to recover the data.

If the files are _really_ important, don't even risk doing that - just turn it off and take it to a professional data recovery serivce (do a Yahoo on "Data Recovery").

And, after you do that, right click on the Recycle Bin, click Properties, click the Global tab, click "Use one setting for all drives:" and CLEAR THE CHECK BOX so it will save those files instead of wiping them immediately!