How can i add a background image to my forum
 

Can someone help me out on this....?

In AdminCP, go to Styles & Templates>Style Manager. If you just have the default style listed, click "Add New Style" and create one with the default as the parent. That way, you'll always be able to use the default as reference.

Now click Go on All Style Options for your style. Go to Body>Standard CSS Attributes>Background ("Body" is the first block under all the folder locations). Replace the contents with...

url(FULL IMAGE URL)

...and take a look at it. (Click the style name in Style Manager, use the jumplist at the bottom of the forum, or change UserCP options to get there.)

If you need the image to repeat in only one direction or not at all, you can specify which and where it is placed in this manner:

url(FULL IMAGE URL) repeat-x top
url(FULL IMAGE URL) repeat-y right
url(FULL IMAGE URL) no-repeat top left

It might also be useful to add a color value so if your image isn't available or doesn't cover the entire space, the remaining background will be the right color. This is for a graphic repeating across the top of the body with the remainder of the body black:

#000000 url(FULL IMAGE URL) repeat-x top

That should be enough to get you started. If you want to fill different or additional areas, either just experiment or use the Color Maps here under Styles & Templates > vBulletin3 Style Reference.

After you finish styling, you can make your style the new default for the site in AdminCP>vBulletin Options>vBulletin Options>Style & Language Settings>Default Style.

many years later thank you for the excellent instructions