URGENT:Toshiba Laptop w/DOS on HD

I have a Toshiba Laptop (1805-S274) with DOS 6.22 installed on the hard drive. I need to load Windows XP, but the CD-ROM drive does not work. The CD-ROM is integrated into the motherboard and cannot be removed or replaced. I have an external CD-ROM drive w/USB 2.0, but the system will not recognize it. How can I solve the problem: ie: Installing Windows XP on the hard drive?

Thank you,
Frenchfries