First up, WARNING! Anything you do which writes to the hard-disk, has the potential to actually erase the file that you've deleted! Therefore, try to do AS LITTLE AS POSSIBLE on that machine. In particular, DON'T download programs onto it, don't download e-mails, don't do ANYTHING if at all possible.
Now, assuming you've heeded the above.... AND you have a spare computer into which you can put the hard-disk, then we have a fighting chance of recovering most - maybe all - of your files.
You'll need to find an "undelete" or "unerase" tool, which will scan the disk for recoverable files. The thing is, when you delete a file, the computer doesn't really erase it; it just takes its entry out of the file table, so you can't see it any more. The actual file is still there. However, the space the file used is now marked as "available", so anything else (a download, for example) can re-use that space. As soon as that happens, part or all of the original file is lost - except to MI5 and the likes, who can do some very clever stuff (this is why you can download "military grade file erase" tools).
Your very best option is, in summary:
- Put the hard-disk in a second computer, as a slave/second drive.
- Scan it with a recovery tool from the second computer; you'll probably get back most/all of your files, if you've not downloaded much (it also helps if you have lots of free space, as Windows might have used that first).
- Once you've recovered what you can, the drive goes back in your computer and all is well with the world.
It's a damn shame you're all the way over the wrong side of the country, or I'd be able to do it for you. If you're headed over Merseyside way in the next few days, let me know, I'm sure we can fix it.
BTW: 2nd best option would be to download an unerase tool to a USB pen drive and run it from there. Just be aware that every minute your computer is switched on risks overwriting some of the deleted data... sorry if that sounds a bit melodramatic, but Windoze is forever writing/rewriting to the drive... same is true of your webbrowser, etc.