After buying a new laptop(XPS L501X) with windows 7 preinstalled, I decided to make it dual boot with windows Vista. I now know about the issue with installing previous versions of windows, and the deletion of the MBR. Normally this wouldn't be a problem, but Microsoft no longer sends install disks with their computers, so there is no way to just re-install windows 7. If anyone can help it would be much appreciated. Data preservation is not an issue, as the laptop is new.
First, it's not Microsoft who no longer sends install disks, it is Dell who stopped it to save the measly cost of printing a DVD. I would simply create another partition from Disk Manager in 7, then reboot from Vista installer and put it there, later, running EasyBCD on Vista to restore the 7 boot option