format reinstall question

I screwed my system up with codec packs and want to reinstall windows vista 64 bit. What is the correct procedure to do this? My hard drive has 2 partitions. I won't loose data stored on the non OS partition will I?

 

Also, Can I enlarge OS partition when I reinstall without formatting second partition? Thanks

 

I'm not exactly sure on this, but have a go.

When you get the choice where to install it, select new partition, and install on it. That way you get a clean install of Vista and keep your other partition. The right click on Computer, click manage, and delete/increase partitions.

 

Thanks, so create a third partition when reinstalling windows, and then after, delete old window partition.