Try the guide below on repairing your WinXP to the Initial state using the WinXP bootable CD without the need to reinstall the drivers or software.
Do take note that there is a need to re-apply the post-patches which are not in the CD.
(Refer to my previous post on how to slipstream/put post-patches into the WinXP bootable CD)
Before proceeding to the guide below, pls get really your WinXP CD Key and the Bootable WinXP CD.
Extracts from "Langa Letter: XP's No-Reformat, Nondestructive Total-Rebuild Option"
"The no-reformat reinstall operation starts with a normal boot from an XP setup CD. Ideally, to save time, use a setup CD that's been "slipstreamed" to include the SP1 and SP2 patches and upgrades.
(Need info on slipstreaming? See "How To Save An Hour (Or More) On XP Installs" and also this third-party site.
Start your PC with the setup CD in a drive, and hit a key when you see the following screen:
Screen One
Boot from your XP setup CD to gain access to the no-reformat reinstall option.
If instead of booting to the CD your PC boots from the hard drive, you may need to modify your PC's "boot order." It's easy and only takes a minute to make the change so that the PC will check for a bootable CD before trying to boot from the hard drive. See this for more information.
Screen Two
Let the CD boot proceed normally and automatically through "Setup is
inspecting your computer's hardware..." to the "Windows Setup" screen.
After a minute or two, you'll see the "Windows Setup/Setup is starting Windows" screen, shown in Screen Three. Don't be alarmed: It's still just the setup process running, and nothing's been changed on your PC yet.
Screen Three
The "Starting Windows" screen is a bit of an overstatement; it's just
the setup process getting going. Windows, as we normally think of it,
isn't running yet, and no changes have been made to your PC.
Soon after Screen Three, you'll be presented with the normal "Welcome to Setup" screen, as shown in Screen Four.
Screen Four
The "Welcome to Setup" screen is poorly worded; the "Repair" option we
want isn't the one explicitly offered here. In fact, the repair option
we want isn't shown at all. See the text for full detail.
The poorly worded options in Screen Four lead many users astray. The only mention of "Repair" here is "...repair a Windows XP installation using Recovery Console..." but that's not the no-reformat repair/reinstall we're seeking. (The Recovery Console Repair option is useful in its own right for fixing relatively minor problems with the operating system, and we fully explore it in the links listed above.)
The repair option we do want--a nondestructive, no-reformat reinstall--is actually hidden beneath the Setup option, "To set up Windows XP now, press ENTER."
The next screen, about licensing, gives no reassurances that you're on the right path for a nondestructive repair/reinstall--in fact, it's the same screen you see when you're setting XP up on a virgin hard drive. But this is only the first of many screens that the Repair option will
borrow from a full-blown setup. Press F8 to accept the licensing terms
and to go on.
The licensing screen gives no indication that this is a Repair and not a brand-new, from-scratch installation. But don't be alarmed. You're on the right track.
Next, the XP setup process will show another screen that you may recall from your initial setup of XP. It searches for "a previous version of Microsoft Windows." In our case, we're not replacing a previous version of Windows, but rather repairing the very same version that's on the setup CD--but that's OK; it's just another poorly worded screen.
Screen Six
Our intent is to repair the same version of Windows as is on the setup CD, but another poorly worded screen makes it seem like you're upgrading a previous version of Windows or installing one anew. But don't let the bad wording alarm you; we're still on track for a nondestructive reinstallScreen Seven finally shows verbiage that's not recycled from the generic XP setup, but is specific to our Repair task.
Setup should find your damaged copy of XP and present it for repair, as shown:
At long last, Setup begins to refer to a Repair option. Here, Setup
should have found your damaged XP setup, which you can select and then
press R to start the nondestructive repair.
The Repair operation replaces all potentially damaged system files with fresh copies from the CD.
Screen Nine
There's no fanfare, but this is one of the nicer parts of the Repair process: Setup retains what it can in the current Registry so that already-installed hardware and software will remain installed.
The system then needs to reboot and will do so automatically. If your setup CD is still in the drive, remove it so that the system won't try to boot from it.
Screen Ten
With the system files freshly copied and the Registry ready for rebuilding, the system needs to reboot. Remove the CD from the drive so that the PC will boot to the hard drive instead of to the CD.
But although the setup screens are the same as what you'd see in a full install, it's still a repair process, as will become clearer in a moment.
Screen Eleven
Screen Twelve
When Setup resumes, it will appear that you're performing a full, from-scratch setup. But don't worry--you're still indeed repairing your existing version of XP.
Screen Thirteen
The Repair version of the setup process skips or shortens many steps because it already has the information it needs from the existing setup. For example, Repair's "installing devices" and the network setup steps are both much faster and require less user input than a new setup does.
The setup screens don't reflect the fact that a Repair proceeds much faster than a normal, full setup. In fact, the time estimates in the setup progress bar will be way off. You'll be done in far less time than the progress bar predicts.
Screen Fourteen
Just as with "installing devices," the network setup proceeds rapidly because Setup can reuse many of the configuration details from the current installation. In fact, a Repair setup takes far less time than the installation progress bar indicates.
When this portion of the Repair is done, you'll see a "completing installation" screen:
Screen Fifteen
The "completing installation" screen means most of the heavy lifting is done, and you're just minutes away from finishing the repair operation.
Setup then reboots your PC again, and this reboot will also take longer than usual. This is normal.
Screen Sixteen
With the bulk of the repair work done, your PC needs to reboot once more and will do so automatically. The reboot will take a bit longer than a standard boot, but this is normal.
After the reboot, you'll be brought to an abbreviated version of the "Welcome To Windows" setup pages.
Screen Seventeen
The Repair process ends with still more screens borrowed from the full setup.
You'll be asked if you want to register and--depending on how badly hosed the previous installation was--you may or may not be asked to reactivate the copy of Windows. Next, the setup software handles the final networking details and then offers a "thank you" screen.
Screen Eighteen
The final steps in the Repair process pass very quickly, and you'll soon reach the last screen in the Repair operation, a "thank you."
In most cases, the system will now reboot for a final time. The Repair is done. It's a normal boot, bringing you to the normal choices for login.
Screen Nineteen
With a final, fully normal reboot, you're done. Your copy of XP shouldbe as good as new, but with all your previously installed hardware, software, and user configuration data undamaged!
If all has gone as planned, you'll find all the user accounts and passwords intact, all the hardware devices set up as before, and all the previously installed software still installed and configured. In fact, if all has gone as planned, the only significant change will be that whatever problem your copy of XP was previously experiencing will now be gone!
You now have a range of repair tools at your disposal, ranging from simple on-the-fly fixes such as Registry cleaning and safe Mode fixes to Recovery Console fixes (see links in the beginning of this article) and, now, a nondestructive, no-reformat repair/rebuild option.
With this information, you should almost never have to face a dreaded start-over-from-scratch reformat/reinstall of XP!"