I need to reinstall Windows XP on lenovo 3000 C100 (an old laptop), but I don't have my Windows XP CD in me. I already have a USB flash drive with Windows in it. The BIOS, however doesn't have an option to boot from USB. I consider running setup.exe from Windows and hopefully the newly-installed boot loader will probe USB devices too and eventually load data from the pen drive. The laptop is not mine and I cannot afford leaving it unbootable.