How to change Windows 7 Theme?

i have download some Theme for windows 7 but i can't load it ?!

i mean i don't know where to open it is there any specific please in windows 7 that we should put the theme there to work or what?

what should i do?How to change Windows 7 Theme?
1. Right click on a empty space on the desktop and click on Personalize.



2. To Change the Theme -

A) Click on one of the available themes.

B) Go to step 4.

3. To Create a Custom Theme -

A) Change the Desktop Background picture and settings.



B) Change the Window Color and Appearance settings.



C) Change the Sounds for the Windows 7 sound events to any sound file that you would like instead.



D) Change the Screen Saver and settings to be used for this theme pack.



E) Change, add, or remove any Desktop Icons that you want to with.



F) Change the Mouse Pointers to use pointers of your choice.



G) Proceed to OPTION TWO below to save your customized theme as a theme pack.

4. To Save the Current Theme to File -

A) Under My Themes, click on the Save theme link towards the right.

B) Type in a name you want for this theme, and click on the Save button.

5. To Delete a Selected Theme -

A) Under My Themes, right click on the saved theme you want to delete and click on Delete theme.

B) Click on Yes to confirm the deletion.How to change Windows 7 Theme?
http://www.howtogeek.com/howto/8887/lear