Yes could can install vista from a 4gb thumb drive. You have to make sure your iso doesn't go over that limit when repackaged. diskpart (note this must be done with Vista's diskpart,its version 6.01..., not XP's, version 5.0...) but once you do thumbdrive prep with a Vista diskpart the instructions do work. I think HP also has a tool to make your thumb drive bootable if your working of a XP machine but I have not used it. select disk 1 clean create partition primary select partition 1 active format fs=fat32 assign exit Copy Windows Vista's DVD ROM content to the Flash Drive Simply issue the following command to start copying all the content from the Windows Vista DVD to your newly formatted high speed flash drive. xcopy d:\*.* /s/e/f e:\