I have a cd/DVD r/w drive but no floppy drive in either computer.

That's nothing serious. I have come across such issue a few days ago, and I tried to reset Windows xp password in safe mode but failed.Thanks to my friend David who introduced me to use Windows Password Reset Deluxe, I solved my trouble in a few miniutes.Besides,he also taught me some methods esle as use reset disk, accessible administrator account ect.
In these methods always one could help you.

There is a way. First you have to install "acronis true image home" software in your pc wich is running with xp. Then make an image or backup of your current system. Then write a bootable recovery CD. After that Put the backup file in the harddisk of the computer in which you want to install the xp. Then insert the bootable CD and restart the pc. Complete the process and you'll have the same configuration of your pc in the new one in wich you set up it.

I have used Windows Login Recovery Professional  to recover Windows xp password forgotten.

1. Start Windows Login Recovery Professional, select Reset local account password for Windows 7/Vista/XP/2008/2003/2000, and then click Next.

2. Insert the CD/DVD or USB flash drive into the computer. Select CD/DVD or USB, click on Burn to start burning a password reset disk.

3. The windows xp password reset disk will be successfully burned automatically then. Then click Quit when finishing burning. Then you can use the password reset disk to rest Windows xp password. It worked great for me. Hope it works for you as well.