My main concern in a recovery is how the files disappeared. If they were deleted and nothing has been done to the area of the disk they were on then you simply undelete them.
If they disapeared because of damage to the filesystem or drive or they have been scrambled or overwritten since being deleted, then you have to get more aggressive.
In your case, you don't know. Let's assume the best case scenario. They were deleted and have remained undisturbed.
Here is the easiest free thing for you to try.
Download copy of Recuva...
(when you install it make sure to uncheck any extra toolbars if you do not want them)
This will probably recover a ton of files but will probably not recover the directory structure so you will get back your data but it will be a chore to go through it all and get what is important out of it.
When you run Recuva.exe
Select OTHER for file type if you want to recover everything.
Select 'In a specific location' and browse to your P: drive
Check 'Enable Deep Scan'
Then wait for it to finish to see what it got that is in an 'Excellent' state.
Select the files that you wish to recover and choose a location to recover them to (preferrably not on the P: drive in case you want to perform a deeper scan or recover other files later)
That should do it if you have not had any other problems with the partition and have not overwritten it since the files were deleted.
Let us know if you have any problems or questions and how things turn out.
Edited by NeverSayDie, 28 February 2012 - 03:46 PM.