probably the easiest way is to use a linux disk
just download the ubuntu live cd (or any linux disk I'm just using ubuntu because I'm familiar with it)
use use imgburn to burn the .iso file to a cd
boot with the cd in your drive so that it boots off of the cd
select the try ubuntu option
once there, navigate to your hard drive to the place where you hid your file
you should see it there, since linux sees all windows hidden folders
optionally, you can go to your 'My Programs' folder (I'm assuming you're using XP
and then look at the names of all the folders immediately inside of the folder, you don't need to go down a second level. most of the names should be familiar to you, and one may possibly be your nameless program. you will have to download the program from where ever and reinstall it.
optionally, you can navigate to the location in which you hid the file then
1. On the Tools menu in Windows Explorer, click Folder Options.
2. Click the View tab.
3. Under Hidden files and folders, click Show hidden files and folders.
If you don't see your hidden file after making sure that windows shows all files, then your file is not there. maybe you put it in another directory?
I hope one of these ways works for you!
the last one you probably want to try first, it works for vista, xp, 2000, me, etc, pretty much all windows distros
the second one you should try next if the last one doesn't work
the first one (the linux disk) you should only try as a last resort as it is time consuming to download the linux installer...
but you should just lock your files instead of hiding them