I recently read a post on here that helped someone change the drive letter for there hard drive so they could install adobe flash player. I have the exact same problem, but when I get to disk management and click on the "change" button it says...
"Windows cannot modify the driver letter of your system volume or boot volume"
If I click on the "add" button, the assign drive letter... and the drop down arrow with letters next to it are all grayed out.
So, I'm not sure what to do from here. Here is the original post I read.
Thanks in advance!