BleepingComputer.com: How to restore with out a installation Disk?

Bought this computer year ago with vista on it. It did not come with any vista software . no installation disk or instructions.
I am not new to a computer but this is my first new computer and after downloads from the internet and instulation of software
and all the useless crap I have. I Want to just keep vista and the files it needs to function correctly. have a 150 GB hard drive on it.
I also partion some disk for ubuntu and I also want that gone. and just keep the vista I bought with the laptop. Kinda like start all over.
I know it all doesn't erase but I have 20 Gbs left and just want everything gone. wiped clean and have just vista running the computer.
I never did a back up untill yesterday. Bought a 8gb flash drive and stored a large file of 5 gb on it this is the back up I have. but the system restore looks like thats what I need to do. But will the partition join together to just one? Can anyone understand me and help me.
Thanks for reading.
Any information is helpful.

What is the make and model of the computer?

Most laptops sold in the last couple of years either come with restore disks, a restore partition, or a method of creating restore disks.

If you didn't receive disks with the computer, then there should be an option buried in the Start Menu to make Restore disks (Sony's may have this in the Help applet).

Finally, some systems have a key indicated in the first screen the shows when you boot the computer that will allow you to restore the computer to it's factory state. Don't forget to backup your stuff before doing this - as a restore of this type will usually wipe out everything!

When you start you computer with Vista and the very first screen comes up press F11. Then you will get into system restore.