Yes, you can. Burn an ISO of GParted : http://http://gparted.sourceforge.net
Then configure your BIOS to run the disc you just burnt and the use of GParted is really straight forward you just have to resize the partition next to the root partition so you gain some space and then resize the root partition to take the new empty space and then apply.
But be careful, save the data on the partitions you are resizing because if the process is stop because of any reason (computer crash or the power shutdown) then you'll probably lose the capability of reading these data. And you should also know that resizing a NTFS partition is fast but resizing a ext3 partition take several hours depending on the size of the partition and the amount of data in these partitions (should be faster with ext4 partitions but I don't know how much) and you'll not have access to your computer during this long amount of time.
Also if you resize a Windows partition Windows will do a checkdisk when you launch it next time, don't stop it, let it run the whole checkdisk if you don't want to have any problems.