|Any partition resizing operation carries a risk of failure, trashing the disk. So the first thing tht you need is a tested backup and a strategy for disaster recovery of the system. Considering the age of your hard disk I would hope that you have this in place already.|
Now you could use a partition resizing program if you can find one that will work with this obsolete OS. A GParted Live CD is a possibility. But, since you now have the means to completely restore your system, why not take the opportunity to do a fresh install creating the appropriate partitions?