OK, don't panic.
Try to open cmd.
Type the following:
-diskpart
-list disk
-select disk( the driver you have)
-clean
-create partition primary
-select partition primary 1
-assign
-active
-exit.
Then try to check if the driver is now accessible.
If not....
Try to download system explorer (search google)
After that..
Open SYSEXPLORER.exe then find the
.script task then right click and select the end process tree. Then use the cmd method.
There you go.