|"it was not supplied by installation DVD"|
Did you read the documentation that came with your new PC? The files & the program to create the Win7 recovery disks should be pre-installed on your computer. If they're not, you ARE entitled to a set of disks, but YOU have to request them from Dell. See the following:
You're going about the dual boot process incorrectly anyway. Win2000 does NOT natively support SATA hard drives & I doubt your new system has a floppy drive, so getting it installed is not going to be an easy task. You have a LOT of reading to do, especially if you're inexperienced. Why would you want Win2000 anyway?