one more question:
I've given it a first try using recuva. recuva has recovered a lot of files, some of them are archives with only numbers as names, some are different types of document formats.

1) will the wallet.dat be a .dat file, so i can easily detect it, or could it be a archive file or something like that?
2) what is the fastest way to detect the .dat file from the recovered files without checking every file by hand?

@jackg
thank you for your feedback regarding ease us. will give it a try if recuva fails.