Hi Zekas,
As far as I am aware you can't have another operating system on there when trying to use the recovery CDs. Not sure how Ubuntu would work with that. The recovery CDs to restore the PC to the way you had it when you first created them. I don't believe that partitioning the drive is going to help, it definitely won't bring by the HP Tools properly. If you try the recovery CDs on a freshly reformatted hard drive and it doesn't work then there is a problem with the CDs most likely. You can order more recovery CDs from HP but there would be charge. If you want to do the downloading Windows 7, I wouldn't be able to help you with that because technically it is illegal.
Thank you,