Sure you can do this, for best results you'll want to grab a 2nd internal hard drive or an external hard drive that you can copy your data to.
Ubuntu can read your vista drive, as long as it's not encrypted, and copy the data to another drive, internal or external. An internal SATA drive or an external eSATA will be the fastest and most reliable way to do this.
Ubuntu can also shrink windows drives if there's enough free space on the drive but that's not recommended without a really good backup of your drive's contents. The shrinking usually works but it's easy to accidentally erase something so why take a chance of losing your data?
Motherboard: MSI NF980-G65 AM3
Processor: CPU AMD|PH II X4 955 3.2G AM3
DVD BURNER: MSI | DH-24AAS-17
Graphics Card: VGA MSI | N9600GT-MD1G GF9600GT
PSU: CORSAIR|CMPSU-750TX 750W
Memory: 2Gx2|GSK F3-12800CL9D-4GBNQ (4GB DDR3)
Case: CASE ANTEC|NINE HUNDRED TWO
Hard Drive: Samsung SP2504C ATA Device (from old computer with Vista OS-32bit)
I am waiting on a good deal for a WD Caviar Black (32mb cache, 7200rpm).
So I made a mistake an installed ubuntu over my Vista. If I buy a OEM or Retail HD, can I install windows on that while I have Ubuntu running?
I am assuming I will have to put the cdrom as the primary booting sequence and the Samsung HD(current hd) as disabled to be able to install Windows onto my other drive.
What are your thoughts? Thanks for the indepth response, appreciate it.
I am a huuuuuge fan of Newegg, all the parts of the comp were bought from there. Not a single problem.
If you're wanting to dual boot Linux and windows you can do that It's pretty easy with GRUB.
Disconnect your other drives, boot from the windows cd install on an empty disk and then reconnect your other drives and set your Linux drive as your 1st boot device and edit /boot/grub/menu.lst to add windows to your boot menu.
This'll look for windoze on your 2nd hdd, hd1. Your 1st hdd is hd0.
run man grub and info grub for more info
You'll also want to take a look at /usr/share/doc/grub-0.97/ after you've installed your docs.