Can't Change Desktop Background

The desktop background won't change on my father's (he's 87) PC.

I've tried to change it ... Desktop Properties -> Desktop tab -> choose any Background (eg Bliss) -> Apply -> OK ... always returns to BacKground NONE (solid blue). Other Desktop operations work fine. Can change on my PC but not his.

He has Win XP Home SP2 w/AVG & ZoneAlarm Firewall.

Worked in the past but not sure when it started to fail. What to do?

First make sure that you are not infected or have any malware

There is a fix but I must caution you that it involves editing the registry

Take precautions and backup the registry, first

To backup the registry proceed as follows:

1/ Click Start

2/ From the menu click Run

3/ In the Run dialog box type: regedit

4/ The Windows registry Editor will now open

5/ Click the File option on the main toolbar and, from the drop down menu, select Export

6/ In the Export Registry File dialog box select All

7/ Now name the file

8/ Finally click the Save button

9/ To return the registry back to its original state should something go wrong simply click on the File option on the main registry editor toolbar and then select Import
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1. Run "Regedit".

2. Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ Windows\CurrentVersion\policies

3. If you see a folder (key) "ActiveDesktop" select it. If not, make a new key and label it "ActiveDesktop".

4. If you see "NoChangingWallPaper", double-click the DWORD value and set it to "0". Otherwise, you need to create a new DWORD value of "NoChangingWallPaper" and set it to "0".

5. Try changing your wallpaper. If this fix doesn't solve the problem, you may also need to make the above registry changes at location: HKEY_CURRENT_USER\Software\Microsoft\ Windows\CurrentVersion\Policies .

Please read through this thread:
http://www.pcreview.co.uk/forums/thread-144156.php

Thanks garmanma.

Try to check for infections, etc regularly but don't live with parents so can't always keep up - will scan.

I put ERUNT on his machine a while ago, so will use that to save registry... will check registry to see if the changes should be made.

Checked out http://www.pcreview.co.uk/forums/thread-144156.php thread ... the problem description there was that the background choices were 'greyed out' ... this isn't the case here ... the background choices look good and all are 'valid' choices - it's just that they don't 'take effect' -- but I'll check the registry for the appropriate keys, etc.

Do you know of anything that could have been done to Windows - other than viruses, etc? Who knows what goes on when he's alone with the machine !