[RESOLVED] How to use make Windows use USB drive as main drive

We use a HP Compaq Presario 5400US computer, Windows XP Prof, 256 MB RAM. It was given to us with the original HD replaced with a 5.98G HD. There is now 452 MB space left, and we get "low drive space" messages frequently. The system is networked with an XP Home computer via a router.

If I bought a 500G external USB drive, is there a way to use it as the main drive instead of the current internal one? Could I use the SUBST command without having to install Windows on the USB drive? I'm hoping it would be an advantage to plug in a larger unit, instead of ordering and installing a 40G internal drive and buying recovery disks.

No. You can't use a USB drive as your main Windows drive. You could probably run WinPE/BartPE on there at the most, but that's not the same a fully functional Windows install.

And it would make the pc much slower since USB connections are much slower.

Thanks to all.