Resizing a boot parition

I'm looking to resize the C drive for a windows XP machine so that I can install windows 7.

Now normally I wouldn't do this because in the past it used to be very risky but my understanding is now programs like gparted can do it relatively safely. All I wanted to know is, has anyone here done it recently? How safe is it to do these days?

If this works I'm going to have to do it on about 15 computers. All of them have at least a 500GB HD and are using less than 50GB. So I have plenty of space I'm just not sure how risky it is. I'm looking for the safest way of doing this. All the computers in question are working 100% and have no issues.

Is gparted-live CD the best way to go for a job like this?

 

Either the LiveCD or LiveUSB version is the way to go because GParted can't resize the partition that it's installed to. Before it expands the partition, GParted will warn that there is always the possibility of data loss and recommend that you back up your data before proceeding. I've done it dozens of times and I've never lost any data. However, to be safe you should backup your partition - just in case. If it works without data loss or errors on the first PC, then you can safely proceed with the others.