Hidden Files and Folders ?

I have Vista when i recently done a clean out i " showed hidden files and folders" to enable a particular scan to run,as in R&RMF , when i opened them i looked in the search folder,and there i seen a file, above recent documents, recent e-mail, etc, called "everything" or C:\ Username\Searches\Everything, in there was hundreds maybe even thousands of files some dating right back to 1999 all the way up to the current day, due to them being in the search folder, i'm assuming these are just files and folders that have been searched over a period of time, now what i am wondering is can they be deleted or not :confused , and the other thing that puzzled me, :confused , was, why on earth is there files and folders in there dating back to 1999 when i only purchased the pc in 2007 :confused , what are these, why are they there and/ or has some one messed with my PC. An explaination would be really appreciated thankyou.

P.S Also within those files there was a batch file and when i tried to have a look at it my AV give it the no no !

Thanks RJ.