Can't boot Win7 boot disc on laptop anymore

[Meresgi]

So I installed Ubuntu on my HP Pavilion dv6000 laptop I got from a sister in law just to screw around, since I've never used Linux very much and wanted to learn. Now I want to sell it, but want to reinstall Windows 7 or Vista back on it before I sell it off on Craigslist or w/e. Only problem is, when I put the boot disc in, it doesn't come up with anything. Priority is set to boot from CD-Rom, other boot discs work just fine, but with the Win7 disc it goes straight into Ubuntu.

Edit: Also to clarify, i'm using a burnt ISO of Windows 7, I know it works because I used it on both this laptop before I put linux on (yeah I know you can do a dual boot) and used it on my Desktop recently for a fresh install.

[Cephius]

I wouldn't rely on boot priority, sometimes it just doesn't work. Manually bring up the boot menu and force it to boot from CD-ROM. Usually hitting F8 during startup does it.

[Meresgi]

Edit: Nvm, it was the ESC key that forced a boot. Thanks Cephius. Hopefully this works.