How to remove partition in Windows 7?

Recently, I re-formatted my Windows 7 PC due to some issues. Accidentally I created two partitions that divide my PC into two drives.
I know that creating partitions is advisable in any case that the default drive encountered any major problems, but I don't really need to divide my computer system into two.
I am more into playing games that requires large size of memory so I want to remove the other partition without affecting or leaving any major issues with my computer.
How can I remove a partition in Windows 7?
Kindly please send some help.
Thanks.
