/dev/sda3 partition full?

[Anoobus]

I'm trying to make a new partition to dual boot ubuntu and windows. This partition is less than a third full. How do I reduce the /dev/sda3 partion without losing data?

[ottosykora]

what type of partition is it?
for windows = ntsf

or for the linux = ext?

if windows partition, then run defrag, then shrink it with the windows tool for that, in this case you will not loose anything, but still it is very much recommend that you BACKUP ALL IMPORTANT DATA first.