|Normally a usb flash has a unique number that MS products try to assign the same drive letter to each time you install it.|
Just manually change the drive letter and each time it should remain the same Use a higher letter.
I think it unlikely that you bought it with a bootable partition.
See a Linux live cd to use linux partition tools to undo .
"Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, are in my top 10