How do i adjust size of desktop background to fit screen

The screen resolution can be adjusted on the PC. This will make the picture expand or contract, there is even a straech option, but the size the picture needs to resized with an image editor.

on your desktop right click go down to properties click go to display go to screen resalotion and change it to fit your needs

Please give more details on what you are trying to do.

If you want to take a picture and make it the total size of your screen as the background of your screen, then just right click on the picture and select Set as Desktop Background. If the size is not what you want then go into the display properties and select the Desktop tab and change the Position to be Stretch. Stretch will fill the whole screen with the picture. Tile will fill the whole screen with multiple little pictures. Center will put the picture in the middle of the screen.

To get to the display properties click Start/Control Panel and look for Display or Appearance and Personalization.

You can also get the display properties by Right Click on an open area of the desktop and select Properties.

on the desk top right click go to properties a window will open select: personalise on windows7 (not home starter edition)

1. Open Desktop Background by clicking the Start button , clicking Control Panel, clicking Appearance and Personalization, clicking Personalization, and then clicking Desktop Background.
   

2. Click the picture or color you want for your desktop background.
   

   If the picture you want to use is not in the list of desktop background pictures, click the Picture location down arrow to view other categories, or click Browse to search for the picture on your computer. When you find the picture you want, double-click it. It will become your desktop background and appear in the list of desktop backgrounds.
   Look for pictures in other locations on your computer

3. Under How should the picture be positioned, choose to have the picture fit the screen, tile, or be centered on the screen, and then click OK.
   

Note

If you choose to have a centered picture as your desktop background, you can also have a color background to frame your picture. Under How should the picture be positioned, click Change background color, click a color, and then click OK.

Windows 7 Starter edition comes with one desktop background, which can't be changed or customized. Please see this link for details.

http://windows.microsoft.com/en-US/windows7/Personalize-your-computer

or if on XP on the desktop right click got to properties select settings and adjust the slider

Windows 7 Starter edition comes with one desktop background, which can't be changed or customized. Please see this link for details.

http://windows.microsoft.com/en-US/windows7/Personalize-your-computer

To change the desktop background

1. Open Desktop Background by clicking the Start button , clicking Control Panel, clicking Appearance and Personalization, clicking Personalization, and then clicking Desktop Background.
   

2. Click the picture or color you want for your desktop background.
   

   If the picture you want to use is not in the list of desktop background pictures, click the Picture location down arrow to view other categories, or click Browse to search for the picture on your computer. When you find the picture you want, double-click it. It will become your desktop background and appear in the list of desktop backgrounds.
   Look for pictures in other locations on your computer

3. Under How should the picture be positioned, choose to have the picture fit the screen, tile, or be centered on the screen, and then click OK.
   

Note

If you choose to have a centered picture as your desktop background, you can also have a color background to frame your picture. Under How should the picture be positioned, click Change background color, click a color, and then click OK.

To change the desktop background

1. Open Desktop Background by clicking the Start button and clicking Control Panel. In the search box, type desktop background, and then click Change desktop background.
   

2. Click the picture or color that you want to use for your desktop background.
   

   If the picture you want to use isn't in the list of desktop background pictures, click an item in the Picture location list to see other categories, or click Browse to search for the picture on your computer. When you find the picture that you want, double-click it. It will become your desktop background.
   Look for pictures in other locations on your computer

3. Under Picture position, click the arrow and choose whether to crop the picture to fill the screen, fit the picture to the screen, stretch the picture to fit the screen, tile the picture, or center the picture on the screen, and then click Save changes.
   

Note

If you choose to have a fitted or centered picture as your desktop background, you can also frame your picture with a color background. Under Picture position, click Fit or Center. Click Change background color, click a color, and then click OK.
Tip

To make any picture stored on your computer (or a picture you are currently viewing) your desktop background, right-click the picture, and then click Set as Desktop Background.
The Set as Desktop Background option

You can add more desktop backgrounds to your collection from the Personalization Gallery on the Windows website.

This can be found in the Help and Support section of Windows on your laptop.

To change the desktop background

1. Right click on your desktop-Select personalize. This will open a window that asks you to select your desktop background
   
   

2. Click the picture or color that you want to use for your desktop background.
   

   If the picture you want to use isn't in the list of desktop background pictures, click an item in the Picture location list to see other categories, or click Browse to search for the picture on your computer. When you find the picture that you want, double-click it. It will become your desktop background.
   

   Look for pictures in other locations on your computer
   

3. Under Picture position, click the arrow and choose whether to crop the picture to fill the screen, fit the picture to the screen, stretch the picture to fit the screen, tile the picture, or center the picture on the screen, and then click Save changes.
   

Note

• If you choose to have a fitted or centered picture as your desktop background, you can also frame your picture with a color background. Under Picture position, click Fit or Center. Click Change background color, click a color, and then click OK.
  

Tip

• To make any picture stored on your computer (or a picture you are currently viewing) your desktop background, right-click the picture, and then click Set as Desktop Background.
  

The Set as Desktop Background option

I'm guessing ur talking about background picture. Am i right?
In that case, you have to set your background picture, in order to fit the desktop. You can do it using left click on ur bakground and select Personalize -> desktop background, where you can find options "Fit To screen", "Tile" or "Center". Select "Fit To screen", then press ok. this should do it.
If you are using Vista as operating system. Before Vista, it varies where you can find the setting windows.

The photos in your computer can be used as screen savers (those files that pop up when you are idle).
1. Right click on your desktop and choose personalize.
2. Select Screen Saver
3. Select Photos
4. Click OK

All of the photos in your pictures folder will be your screen saver.

If what you want is this picture to be your background (the file that shows on your desktop all of the time)
1. Right click on your desktop
2. Select personalize
3. Select Desktop Background
4. Change the "Location" to Pictures from its setting of Windows Backgrounds
5. Select a picture
6.Click OK. It is automatically sized to your desktop.

if you're using Vista, you can right click on your desktop and choose personalize then choose Desktop Background. at the bottom part of the Desktop Background page you will see options on how you want the picture to be seen. choose the first one, which is Fit to screen, if you want the picture to be seen in the whole screen.