You already have Eclipse Indigo, but you want more. That is a good thing.
Indeed, you want be able to connect your projects with a software versioning and a revision control system, and this directly from Eclipse.
You need SVN!
Help > Eclipse Market Place... > Write Subclipse in the Find input area.
Click Install on the right of the Subclipse details.
Accept all and restart Eclipse.
If you have a 64 bits Java Virtual Machine, you must download the JavaHL for 64 bits.
Here the website: http://www.sliksvn.com/en/download
Choose the Slik SVN 64 bit edition for Windows.
Install it and restart your computer.
You can now use it.