Microsoft has ask me to re-register my xp software?

It usually takes a long time (months) for Windows to kick you off for an invalid key or demo mode. In your case XP must have updated and loaded a Window Authentication update then flagged you with an invalid (pirate) key. You very well might have to re-install the OS.

that's probably that you installed your XP in a non valid serial number,try to get a valid serial number
did you use an original XP cd when you installed your XP?

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.

Windows Vista and Windows 7
Start-

Hi,

Welcome.

Check if the sound driver is installed and up to date, follow these steps to find that.

Step 1:

1. Click Start and then click Run.
2. Type devmgmt.msc in the Open box, and then click OK.
3. Check for Audio and if you see any yellow exclamation next to sound then either audio drivers are not installed or it needs to be updated.

Step 2:

To check manufacture try this.

1. Click Start and then click Run.
2. Type dxdiag in the Open box, and then click OK.
3. Click the Sound tab.
4. Under Device, look for Name, and under Driver, look for Provider.
5. Click Exit.

Contact the manufacturer of the sound driver to request an updated sound driver.

If you dont see any problem with device manager (Step 1)
try below steps

Step 3: Use the Windows XP Sound Troubleshooter

loadTOCNode(2, 'resolution'); Windows XP includes a troubleshooting program which could help you resolve your sound issues. Start the Windows XP Sound Troubleshooter automatically or manually and then answer each question on-screen in order to try to find a resolution.
Start the Sound Troubleshooter loadTOCNode(3, 'resolution'); If you are already familiar with Windows XP Help and Support Center, click the following link to start the Sound Troubleshooter:
Sound Troubleshooter (hcp://help/tshoot/tssound.htm) OR

Start Sound Troubleshooter manually by using the following steps:

1. Click Start, and then click Help and Support.
2. Under Pick a Help Topic, click Fixing a problem.
3. In the navigation pane on the left, click Games, sound, and video problems.
4. In the topic pane, on the right side, click Sound Troubleshooter.

Step 4: Update your Media Player software

loadTOCNode(2, 'resolution'); If the sound problem that you are experiencing occurs when you use a media player such as Microsoft Windows Media Player, try updating your media player software. To obtain the latest version of the Windows Media Player, visit the following Microsoft Web site:
http://www.microsoft.com/windows/windowsmedia/download/AllDownloads.aspx (http://www.microsoft.com/windows/windowsmedia/download/AllDownloads.aspx) Determine whether you can now hear sound. If you can hear sound, the issue is resolved.

Regards,
Chandra Shekar G
PCS365.10
Bangalore.

Click Start menu, and then click the Run icon.
In the small box that Opens, type the three letters: cmd then click the OK button.
In the command prompt window that just opened (a black background and white text), type the following commands, pressing the ENTER key on your keyboard afterwards:

regsvr32 msxml3.dll

Now type the word: exit and the window will close.
Now Reboot and try and Microsoft Windows Update again....

If it fails with the 0x8007007E error again try Step 2

Step 2) - Windows XP Only...

Now lets update your system with the latest Microsoft XML Parser (MSXML) version 3.0 SP4

Download Here (use the msxml3usa.msi for the English language version.)

Notes....

a) You will need to reinstall MSXML 3.0 SP4 if you upgraded to Windows XP from a computer running one of the following operating systems:

- Windows 98

- Windows ME

- Windows NT 4.0

b) Windows 2003 server
ships with version 3.0 - SP4 and so you do not need to install it.

c) Occasionally, setup may need to reboot the computer but fails to inform the user. Therefore reboot your machine just in case. Then try Windows Update again...

d) To install a localized (e.g. English) version of MSXML 3.0 SP4 on a system different from the previously installed version/locale (e.g. French) of MSXML 3.0 SP4, complete the following steps:

Unregister the existing installation package by executing the following command in a Command Prompt window:

msiexec /qn /x {45534579-B75B-4A42-953B-2EF8E1DEB4F3}

Now install the new localized version of MSXML 3.0 SP4.

If it fails with the 0x8007007E error again try Step 3


Step 3) - Windows XP Only...

Scan For Missing/Corrupt System Files...

Windows XP comes with a wonderful tool called System File Checker (SFC) It scans and verifies the versions of all protected system files after you restart your computer... However it can sometimes miss a problem, so we can run the tool now to replace CABINET.DLL and URLMON.DLL if there is a problem with them:

To Do This:

Click Start menu, and then click the Run icon. In the small box that Opens, type the three letters: cmd then click the OK button. In the command prompt window that just opened (a black background and white text), type the following command:

SFC /scannow

and then click OK


You must be logged on as a member of the Administrators group to run SFC..

You will need your Windows XP CD during this procedure if SFC needs to get an original file. Please remember that Windows XP can have multiple instances of a .DLL file and remember which version is for which program.

Notes....

I have been asked if it is possible to have a "progress meter" show when SFC runs... This is the registry hack you need. PLEASE do not go messing with your registry if you do NOT know what you are doing!

System Key: [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]

Value Name: SFCShowProgress

Data Type: REG_DWORD (DWORD Value)

Value Data: (0 = disabled, 1 = enabled)


IMPORTANT: This article will cure the 0x8007007E problem for many of you. However if it does NOT then I would love to here from you. Or, did YOU try something else that worked? Then email me the fix too!

You may also find these error codes useful - for future reference, especially when trying to figure out error messages in the Windows Update log! (They are only given here as a guide to general problems and will require further research on your part to resolve the particular problem you may be having.):
0x800C0002, 0x800401E4 and 0x80072EE5

The address of this site is not valid. Check the address and try again.

0x800C0003

Cannot start an Internet session.

0x800C0004 and 0x80072EFD

Cannot connect to the Internet server.

0x800C0005

Cannot locate the Internet server or proxy server.

0x800C0006 and 0x80072EFC

The site reports that the item you requested could not be found. (HTTP/1.0 404)

0x800C0007

The Internet site reports that a connection was established but the data is not available.

0x800C0008

Cannot download the information you requested.

0x800C0009

The item you requested requires proper authentication. (HTTP/1.0 401)

0x800C000A

The Internet site cannot return the object you requested. (HTTP/1.0 403)

0x800C000B and 0x80072EE2

The connection to this Internet site took longer than the allotted time.

0x800C000C

The site reports that the request is not valid.

0x800C000D and 0x80072EE8

The required Internet protocol is not installed on your computer, or the Internet address you requested may not be valid.

0x800C000E

A security problem has occurred.

0x800C000F and 0x800401EA

Cannot open the specified file.

0x800C0010

Cannot start the program needed to open this file.

0x800401E6 and 0x80040154

No program is registered to open this file.

0x80004004

The hyperlink cannot be followed to the destination.

0x801901F8

The transfer request timed out while waiting for a gateway. Resume the job at a later time. (HTTP Error 504)

0x801901F7

The service is temporarily overloaded and cannot process the request. Resume the job at a later time. (HTTP Error 503)

0x80190194

Make sure VBScript is installed, turn off script blocking in anti-virus and personal firewall software, reregister VBScript, and then install iTunes." Resolution Download and install the latest version of iTunes.
Install the latest VBScript engine from Microsoft for your Windows OS platform Windows 2000 Download and install VBScript version 5.6 for Windows 2000 from Microsoft, and then try installing iTunes or QuickTime again. Windows XP Download and install VBScript version 5.7 for Windows XP from Microsoft, and then try installing iTunes or QuickTime again. Windows Vista No download necessary. The latest VBScripting engine (version 5.7) is already included with Vista. Follow the steps below to register the VBSScript again if you still have this issue in Vista.
Register the VBScript engine again If the latest VBScript engine is already installed, register it again. Note that you must be logged in as administrator or logged in as a user with administrator privileges for the computer to execute these steps.
For Windows 2000 or Windows XP: 1. On the Start menu, click Run.
2. In the "Open" field dialog box, enter the following command and click OK:
regsvr32 vbscript.dll
3. A message should appear stating that the "DllRegisterServer in vbscript.dll succeeded."
4. Click OK and try installing iTunes or QuickTime again.

Normally registration is asked only when the system is reinstalled or newly installed.

Ensure that the computer is not asking registration for a different product, for example a newly installed printer, new microsoft Office etc.

If you reinstalled windows, or did some operation on the system as registry clean etc. , and you think it is a genuine registration request, you can decide to register, or ask not to have the request prompted again.

If you think this can be a virus or a non genuine request from fake software contact Microsoft here: Microsoft Contact

you office software may have crashed... try reinstalling you office that may fixed the problem... also check the microsoft updates site for bug fixes...