Hi there, firstly is it a large USB drive or a newer USB 3.0 thumb drive ? ( both will show as Fixed disk type ) If its a large USB drive ( a hard drive in a carrier) then it will be always seen as a "fixed disk" type of drive and this cannot be changed , if, however it is a modern USB 3.0 thumb drive then you can simply re-format the drive. Newer USB 3.0 thumb drives are sold with an exFAT file system ( the new standard for removable drives in win 8 and up computers , also this format makes the drive compatible with Mac , without any problems plugging the drive into either Mac or Windows, So basically if you need to use the drive between Mac AND windows then best left as exFAT format - but - if you need to use with JUST windows then simply right click on the drive icon and choose format and then NTFS as file system , once formatted the drive will be seen as removable media from within windows. ( or is it possible you want to use the drive as a boot drive , installation tool ?) If so I would recommend a tool called Easy2Boot , more information can be found on the Easy2Boot.com website - just type Easy2Boot in browser search bar. Hope info helps. Regards