I have the option of Dual booting Vista and Vista Ult. but the problem is vista ulti is... not completely installed, now I'm stuck with the dual boot option every time I boot up my computer. I'd like to get rid of it but I don't know how. Reformatting isn't an option since I don't have any extra HDD around to backup my stuff and I'm really tight on money right now as well, so buying a new HDD is something that can only be done very late in the future.
Other than disabling dual-boot in a way I'm not currently aware of, you can try installing Vista Ultimate properly, then uninstalling it. I assume you've placed both OSes in their own partition? In that case, you can always copy all important data into your Vista partition, and format the Vista Ult partition.
You'd better get a hard disk soon man. Nothing beats backup!