XP Setup from USB Flash Drive

Hi All,

I am tring to create a bootable XP setup usb key. I had a 1GB key which made it bootable and goes through DOS mode section of setup but after reboot from harddisk give me an error could not found {Windows}\system32\hal.dll. I am pretty sure it cause by wrong entry in boot.ini. To make the USB work I have to put SetupSourceDevice=\device\harddisk1\partition1 into txtsetup.sif. any tip how I could replace boot.ini after file got copied and befor restar?