Why would ai and pdf files instantly disappear on My Book external Drive?

Please Help!  I had been working on an illustrator file for 2 weeks and had it saved in my Mybook as a PDF and illustrator file.  I went to email it but at 49 Meg it was too big to attach to my email.  I tried saving it as a .eps and my computer completely froze so I had to restart the system.  When I fired back up the shortcuts for my files were there but the originals are gone.  I ran diagnostics, nothing.  I tried to do a system restore, nothing.  I tried to do a file recovery on one of the free trials, nothing.  

Hi,

Have a search for 'AITEMP' on your HDD, if you are lucky the temp file was not cleared out when you had your crash. You will probably find a few files with this string in it.

You could try renaming it to .ai or .pdf and try opening it in Illustrator. There is no guarantee that this will work but at the amount of options you are looking at this is probably the best.

Likely these are in you scratchdisk folder so you could look there first.

If that does not help, then you can try to use a utility Illustrator Recovery Toolbox. In about such cases like yours it often brings many benefits, at least to me it is very helpful. I think that you will also be able to help.  http://www.oemailrec...r_recovery.html

It is also possible this information will be of interest to you.

https://forums.creativecow.net/thread/245/858214