1. Just buy a second hard drive and copy your data files to it. Then delete
the data files from the first hard drive.
2. Or use a third-party partitioner (Acronis Disk Director, Gparted, etc.)
and create a second partition on your single hard drive. Then copy the data
files to the second partition, etc.
3. Or buy an external hard drive and image your system with something like
Acronis True Image (which can do incremental imaging also) and keep the
image on the external hard drive. You'll be able to get back to a working
system in a few minutes.
4. Or start over completely (obviously the least desirable choice). Back up
your data to external media and clean-install Windows, creating the desired
partition scheme during installation. You still will need to create and
implement a backup strategy, so #3 looks best to me.
Elephant Boy Computers - Don't Panic!