dual install

[norman]

I am introducing my brother to the delights of Ubuntu and, so far, he is
very impressed. He has now decided that he will install Ubuntu but
retain his Vista. His hard drive has two partitions, one for his Windows
system and software and one for data. I have installed Ubuntu before on
machines when there has been only one partition and I would be grateful
if some kind person could confirm that it will be OK to go ahead and
install Ubuntu on my brother's machine and that the two existing
partitions will be preserved.

Thanks for your help.

Norman