Yes, partition magic is commercial software.
I used BootIt NG, available from
www.terabyteunlimited.com
Download the program, run it to create a boot floppy, restart your computer with the disk in your drive. It will allow you to resize your existing windows partition without destroying data.
Note that there is always a chance that any partitioning program could destroy your data. Make sure you back up any important files just in case the worst happens
Nathan
[edit]
You should just be able to make some free space. The install program will normally allow you to create the neccessary partitions out of the free space and format them.[/edit]