The Recycle bin won't hold a huge number of files deleted all at once. You likely didn't notice it but Windows File system gives you a warning when you try to delete large blocks of file that they won't fit into the recyle bin.
But all is not lost! Windows doesn't really delete your files...it just deletes the index of your files. They are still on your hard drive and most should still be recoverable. But you MUST quit using your PC (much) until you restore them or Windows will start allocating the space held by them now for other files. And do NOT turn off your PC until you've done the restore.
Go to HERE for some basic info...including to STOP USING THE COMPUTER (have I mentioned that already?) other than to download the recovery tool. I've used Restoration before and it works very well, but there are others like Recuva that do the same thing.
Grab the file (preferably from another PC if you can so you don't screw with this one), stick it onto a memory stick or floppy, then run it on the PC that held the files. Most should be recoverable.
Good luck!

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