XP installation - CISIF.DLL is not a valid windows image

Generally this error means you got the wrong version of the dll installed. IE you are running XP and installed one for Win98 and the one for XP is slightly different.

Sometimes this is a path issue and all you need to do is to copy (not move) the DLL and put it with the others in System32

In addition there are a few specific problems which cause this type of error
http://support.microsoft.com/kb/907300

Autocad also has a similar problem for which there is a patch.
So please be more specific.
Is this just one dll? If so what is it?
What application and what consequence?

You should also try reregistering the dll
using your example
go to start / run and type
regsvr32 xxxx.dll
hit enter and wait for it to say success

You have not said which OS you are using so; from http://support.microsoft.com/kb/943144

When you try to install Windows updates from the Windows Update Web site, the Microsoft Update Web site, or by using Automatic Update, you receive a message that the update is not installed successfully. Additionally, the update is not displayed in the update history.

You may experience this issue in the following scenarios:

Scenario 1 You try to install updates after repair a Windows XP installation by using the Windows XP CD.
Scenario 2 You perform the following operations before you try to install Windows updates:

You perform a new installation of Windows XP Service Pack 2 (SP2).
You visit the Windows Update Web site, or the Microsoft Update Web site.
Note When you visit the update Web site, the latest version of Windows Update software will be installed in your computer.
You install Windows XP Service Pack (SP3) without a restart.
You try to install Windows updates after the install of Windows XP SP3.

Then cause ;

This issue occurs because the Wups2.dll file that is included in the latest version of Windows Update is not installed correctly.

For scenario 1, the registry entries that correspond to the Wups2.dll file are missing after the repair install of Windows XP. The release version of Windows XP does not contain the Windows Update software.

For scenario 2, the registry entries that correspond to Windows Update are changed back to the Windows XP SP2 version if you did not restart the computer before you install Windows XP SP3. The registry entries for the Wups2.dll file are changed to pointing to the Wups.dll file that is included in the release version of Windows XP SP2.
To resolve this problem, use one of the following methods;

Method 1: Download and install the Windows Update Agent,
For an x86-based computer; http://download.windowsupdate.com/WindowsUpdate/redist/standalone/7.4.7600.226/WindowsUpdateAgent30-x86.exe

For an x64-based computer http://download.windowsupdate.com/WindowsUpdate/redist/standalone/7.4.7600.226/WindowsUpdateAgent30-x64.exe

Method 2: Register the Wups2.dll file,

To have MS register the Wups2.dll file in Windows for you, go to http://support.microsoft.com/kb/943144#FixItForMeAlways.

If you prefer to fix this problem yourself,

To register the Wups2.dll file in Windows, follow these steps:

1. Stop the Automatic Updates service. To do this, follow these steps:
a. Open the Command Prompt window. To do this, click Start, click Run, type cmd, and then click OK.
b. At the command prompt, type the following command, and then press ENTER:
net stop wuauserv

2. Register the Wups2.dll file. To do this, follow these steps:

a. At the command prompt, type the following command, and then press ENTER:
regsvr32 %windir%\system32\wups2.dll

Note For a computer that is running Windows XP Professional x64 Edition, type the following command, and then press ENTER:
regsvr32 %windir%\syswow64\wups2.dll

b. Click OK if you receive a verification message.

3. Start the Automatic Updates service. To do this, type the following command at the command prompt, and then press ENTER:
net start wuauserv

4. Exit the Command Prompt window. To do this, type exit at the command prompt, and then press ENTER.

Have you tried doing a file search for nvdesk32.dll on your c: drive? You may find it in another folder. If you find it in another folder just copy and paste it to the c:\windows\system32 folder. Good luck.

u have to install dll file from internet, run registry cleaner reg in out to easily fix it

Your Operating System is corrupted, probably by a virus or a program you recently installed.
The best solution would be to reinstall your Operating System (OS).
Remember to back up your data before OS installation.

CAUSE
Windows XP SP3 introduces a new .dll file that is named Wlanapi.dll. This file is installed in the %WINDIR%\System32 folder. Certain device driver installations for some third-party wireless network adapters also install a Wlanapi.dll file in the %WINDIR%\System32 folder. If such a file is installed in this folder before you install Windows XP SP3, the Wlanapi.dll file that is associated with the network adapter is replaced by the file from the Windows XP SP3 installation.

RESOLUTION
To resolve this issue, check the Web site of the wireless network adapter's manufacturer for the latest device drivers that are available for a Windows XP SP3-based system. Then, download and install the latest device drivers for the wireless network adapter. Source(s): http://support.microsoft.com/kb/950720

You may be able to perform a restore, From the start menu chose programs>accessories>systemtools>System Restore
Choose a restore point that you think has a best date and time when your pc was working better.

See the game requirements.

It means : SP3 introduced a new wireless lan application programming interface (windows program that interacts with your wireless card/device driver)

solution : check your wireless device or computer manufacturer for updated (works with SP3) driver.

is that an Microsoft Official Service Pack? anyways. Try using a System Restore and choose a restore point on your problem.