I know this thread is a little old, but it has some useful info. and I can share my useful info. if anyone is interested. I would like to know something: There are already ways to partition a usb drive with multiple partitions with various tools, and it's possible to show the drives in windows with a tool/glitch I know w/o any filters,etc. BUT MY QUESTION IS: will making the 1st partition of the usb to be DOS-bootable allow the usb to be fixed in all versions of windows? Or simply, will it be shown as a fixed drive if the usb is loaded onto a new computer w/o the microdrive filters? BTW, if u want to know how I manage to partition my usb drives, I used MiniTool Partition Wizard to resize and set all partitions as Primary and one Active, then I safely remove the usb drive and run the showdrive.exe command found in %systemroot%\system32\showdrives.exe, which shows all the drives. It works for me, however, it wont work on certain XP Live CD's. I find that in Safe Mode it works flawlessly, so it could be a windows service sometimes. For the "showdrives" trick, in certain scenarios it will only work if you unplug the drive 1st before executing showdrive.exe, any further ejects can cause the USB not to show until you reboot your system. Heres a tool i like messing with, BOOTICE.EXE (Latest 0.9 build). My favorite MBR is Wee63.mbr, you can easily customize which loaders and where the loaders are located on the drive, so if you have a multiboot USB with one partition, you can use different loaders in different directories, and just customize your menu.lst or .ini file to direct each bootable img or installation DIR. It's even better with multiple paritions, because all you have to do is just direct the loaders in wee63.mbr w/o any further file editing. Also, you can direct boot manager loaders, like plpbt.bin, which allows you to chose which media device and partition to load from during boot (i highly discourage plpbt.bin because it has some rediculous bugs when loading a usb with multiple partitions, that contain a loader that is the same as the 1st partition on the drive).