I'm new to UBUNTU, I have an old PC and wanted to try it out. Installed it using the windows installer and it created its own partition. I would like to uninstall windows and run this as the sole OS. Can anyone help?
Since you installed Ubuntu using the WUBI, which means you did it from inside Windows it will be difficult (but possible) to have only Ubuntu. What I highly recommend for your case is just to burn the ISO image on a Pen Drive or CDROM/DVDROM and install it via the Standard Ubuntu installer (Booting from the CD/DVD/USB Drive). That way you can even choose to remove Windows if you want and have it only with Ubuntu.
You can also even repartition the hard drive to have a space for Ubuntu and a space for Windows.
Basically with the Ubuntu installer you have a little more freedom compared to WUBI. And to top it off, it is very easy to use.
If you like Ubuntu you can burn the ubuntu .iso to a CD or put it on a flash driver and install it.
When you install it, simply use the entire Hard drive (Erase disk and install Ubuntu). No need to uninstall Windows.
Alternately you can migrate your wubi install, but that will likely take more time and effort.