Q I installed Linux Mint and, being new to Linux, followed the instructions about partitioning. However I was installing on a laptop with Windows already taking up two partitions therefore when I partitioned I found that (only being allowed four partitions or something) I am unable to access a large chunk of my hard drive. I dedicated 10GB to / and 512MB to swap, but the partition editor in Mint won't let me do anything.
A A PC hard disk is limited to four partitions, one of those wonderful limits from the days when people still thought it was fine to say "no one will ever need more than..." The solution is a kludge, but one that works very well, to make one of those four primary partitions an extended partition, which can act as a container for so-called logical partitions. In this way, it is possible to have a lot more partitions - as many as you have space for, in fact. Your problem is that you have already used up your four primary partitions and so have nowhere to create an extended partition. The solution is to remove one of your existing partitions (the one next to the unused space) then all of that space can be used for logical partitions. If your partitions are in the order you gave them - Windows, Windows, Linux root, Linux swap and then the unused space - you only have to remove the swap partition to be able to make use of all of the space, and you can do this while the system is running. Open a terminal and run
sudo swapoff -a
to disable your swap, then run the partition editor as you have done before. Delete the swap partition and you should now find that you are able to add extra partitions. You don't have to worry about the primary/extended/logical nuances, just tell GParted to create a partition. If it asks whether you want to create a primary or logical partition, answer logical and it will take care of creating an extended partition to hold it. The first thing to do is create a new swap partition to replace the one you just deleted, which will be called sda5 - logical partitions are always numbered from five, no matter how many primary partitions you have. After you have finished editing the partitions, you will need to enable your new swap partition. Go back to your terminal and run
mkswap /dev/sda5 sudo gedit /etc/fstab
Find the line that refers to swap and replace the UUID=xxxx part with /dev/sda5 (or whatever your new swap partition is called). When you reboot, you will still have a swap partition and another 30GB of disk space to play with.