Windows XP PowerPacker 1.0 RC9
Windows XP PowerPacker was made with the BTS DriverPacks in mind. Basically it does just about everything you need to do to add a windows XP load to your MultiBoot Disk.
It will gather the needed files from your source XP CD and put them into a directory you specify. It will grab the DriverPack Files and install them. It will create a boot directory for your load and even hex edit the files that need to be HEXED to allow you to boot to it. It will put the needed info into the boot list so you can select your XP load. It makes testing the DriverPacks very easy!!!
Download: Windows XP PowerPacker 1.0 RC9