Lost Folder in "My Documents"

I have lost an entire folder containing anout five years' worth of client reports, invoices, etc. for one of my consulting clients and need help ASAP. This is what I have done so far: checked through the Search function by folder title, unique words, client names, etc.; activated my Dell DataSafe account (similar to Mozy); ran Recuva, Malwarebytes Anti-Malware, used Spybot - Search & Destroy, ran Auslogic defrag. Whle running the "Search" function in WIndows XP, I can see about four files for a a few seconds which I need but very quickly I get the message that "Windows has encountered a problem and needs to close." which it does. All of my other client and peronal files in My Documents are current and can be opened.
I cannot understand why the Dell DataSafe service which I have used for over two years is also unable to retrieve the client file. Any help would be greatly appreciated.

 

You might try Chkdsk, since it sounds like the folder is there, but maybe corrupted.
Can you tell by your disk space if the folder is still there somewhere?
You might be able to find it in DOS.

 

The most effective search tool I know of is Everything. You can use all or any part of a folder or filename and it will list all possibilities - fast! The entire computer is included in the search, including hidden and system folders.