laptop fails to read any usb flash drives

Hi all, I'm new here. First of all excuse my english and spelling.
I have a dell xps i7 that runs windows 7 home. Lately the laptop can not read any usb sticks (flash drives), though it does recognize it.
When ever I insert one in, the laptop will make the sound of inserting a usb device, but at first it won't show up in "my computer". After a couple of minutes It will suddenley appear as "removable disk" and not under it's name.
When I open it with windows explorer It is empty (even if it is full of files) and if I try to copy a file into it I'll get an error message "could not find this item. This is no longer located in computer. Verify the items location and try again".
When I check the usb stick properties it shows 0 bytes used and 0 bytes used space.
In disk management it apears as"no media" with and any attempt to format did not work.
The problem seems to be with the laptop and not the usb stick. I've tried several usb sticks from different manafactures and all have the same simptoms and they all work fine on different computers.
I've tried to uninstall the usb drivers and reinstall but that did not work.
Anybody with ideas out there? I sure would appreciate any kind of help because I am desperate