First off, stop using your computer. When a file is deleted or moved what happens is the pointer is deleted, not the file itself.
Think of a library where all the books have blank covers, but they have a special code written on the binding. The only way to find the book you want is to go to the card catalog, find the topic, write down the number of the book you want, then go to the stacks to find the number that matches up.
Imagine that you hate penguins. You go to the card catalog, find the books on penguins and rip the cards out and put them in the shredder. The books about penguins still exist, but you don't know which books they are (books in this library are sorted randomly).
Whenever the librarians realize someone destroyed one of the cards, they can either
A) write it off and buy another book about penguins.
B) go search the library for books about penguins, then recreate the card and put it in the card catalog.
It sounds like you have a couple problems going on.
1- it sounds like you may have removed programs, not data. This is a crucial distinction. Programs like Word, Windows Media Player, iTunes, Adobe Acrobat Reader, etc are the portion of your computer that you interact with. Those files should (generally speaking) should not be messed with (other than updating them). When you move them or delete them your computer loses the ability to access certain types of files. For instance, if you move or delete Word, you won't be able to open word documents.
You need more help than a web forum can give. You probably need to reinstall your programs (and probably repair windows) if you were moving program files. Second, you need to learn the difference between data and programs. Store your data in a predictable place (mine is located in a folder called Matt). When I bought an external hard drive, I simply copied that folder (c:\matt) to my external drive. I didn't mess up any programs, just moved the data.
As to recovery- if you keep using the computer, the sections of your hard drive that had files may be overwritten and destroyed.
Going back to the library analogy-- periodically the library runs out of space, so they take books that don't have a matching card in the card catalog and burn them. This makes room for new books. This is (generally) not something that can be reversed.
There are many undelete/file recovery utilities available (most for a fee). You could also send your drive to a company that specializes in data recovery. Again, this is not easy to fix, and probably won't happen on the web. Find someone local that has experience recovering lost files and pay for their assistance if the files are really that critical.
I wish you the best of luck.
Matt