Issue with copying folder to exteranal drive

I have Vista Home Premium 64bit, and I am simply trying to copy a folder from my hard drive to an external drive. When I do this, I get the message :

Could not find this item

This is no longer located in C:\Users\SaminDallas\Searches\Documents\File.ppt

Does anybody know whats going on and how to fix this.

This is messing up my means to make backups.

Is there something going on with the Searches folder ? I navigated to the Searches folder and do see the files there - but I have no clue what this Searches folder is doing.

Any help would be appreciated,

thanks,
SaminDallas

ps. this has always worked in previous versions of Windows XP, etc..