Windows Tweaks Logo Microsoft PC Help - 02 blue red
Windows Tweaks Logo Microsoft PC Help - 09 white 120

Windows XP Service Pack 1 - 100% Processor utilization by Explorer.exe after SP1

November 29, 2013
Updated: December 6, 2021
Quick overview:

Shortly after you have installed Service Pack 1 on your Windows XP, you will notice that the Explorer.exe file in your task manager (CTRL+ALT+Del > Processes) is using 99 or even 100% of your processor, which is causing your computer's performance to plummet. This behavior occurs on some computers for a few seconds to a minute, which severely degrades performance. We have put together several solutions for you so that you can utilize the full performance of your computer at all times.

Explorer.exe is not only, as the name suggests, the executable file of the Windows Explorer file manager, but also includes the entire taskbar and access to the desktop. It is, so to speak, the heart of the Windows interface and is therefore susceptible to errors from many sides. To rule out the above-mentioned error, you must do the following:

Setting performance options under Windows XP

1. Some in the Background running programs from third-party manufacturers attach themselves to the Explorer.exe file in order to extend Windows Explorer with more or less useful functions. One example is Norton AntiVirus, which also places an icon here and intervenes directly in Windows Explorer.

After you have installed SP1, the explorer.exe file has been slightly modified and improved. Since some programs can no longer cope with the new and changed functions, they stop in the middle of their calculations and program code and constantly repeat their commands, which leads to a CPU load of 100% until Windows terminates these programs. To avoid this error, you must proceed as follows:

Click here to find out how to deactivate the hidden autostart programs and activities. In most cases, these are behind the problem - if necessary, you would have to uninstall your programs one by one until you have determined which of the applications is the culprit.

2. Owner of the main board (motherboard) Asus P2B have also complained about excessive CPU utilization after an SP1 installation.

- Read in the MSKB how to work around the problem.

3. Also Viruses or Trojans are in some cases responsible for permanent work in Explorer.exe and have the sole function of slowing down your computer. We therefore advise you to use the latest virus scanner with its latest update on your system and to scan the hard disk for small intruders.

- Visit the page of the famous AntiVirus 2002 manufacturer Norton.

4. If this problem only occurs with some folders that contain videos, then the preview function of Windows Explorer is responsible, which opens the videos and then selects an image as an icon. This can also lead to full capacity utilization, especially on low-performance computers. To avoid this, you must do the following:

Click in succession on Start/Execute and type regedit in order to Windows registry Editor. Now navigate through the keys HKEY_CLASSES_ROOT\SystemFileAssociations\.avi\shellex\ PropertyHandler and delete the value Default.

This value must be safely deleted so that the preview does not appear

The file shmedia.dll is also responsible for this misery: It reads the properties of video files (length, resolution, etc.) and is then in an endless loop if the file is incomplete or incorrect. The CPU load is of course also affected. Click again on Start/Execute and type regsvr32 /u shmedia.dll to deactivate this analysis (as above). The difference here is that not only AVI files but also many other video formats (avi, mpeg, wmv) lose this preview. So if you have problems with other formats: This will solve them! To undo the command, all you have to do is press regsvr32 shmedia.dll type in. Many thanks to Aberrossi for the tip!

5. The next troubleshooting option can be found in the basic system drivers: The IDE (hard disk) controller Drivers that were previously updated by Via4in1, for example, are now back at an early Microsoft stage, which not only causes the performance of the hard disk to plummet but also, due to the primitive use of Windows XP cache management, the speed of the processor.


Only the reinstallation of the via hard disk drivers solves the new problems

Also, some users report not only overwriting their hard disk drivers but a complete update of the Sound cards and graphics card drivers.

Update the hard disk driver: VIA 4in1 4.43
Sound card driver: The complete list of manufacturers
Graphics card driver:
The complete list of manufacturers

Windows NT owners also had this situation when they updated their computers with Service Pack 1-6. It seems as if Microsoft has not taken a step into the future, stability and speed, but a step back into the dark beginnings of 32-bit operating systems.

6. Since Service Pack 1, a certain Optical setting of Windows XP the fact that the Explorer.exe seems to go crazy. This concerns the folder views in Windows Explorer, which become a CPU killer due to a visual effect - strangely enough only after the update has been installed.

Click with the right mouse button on Workplace and select Properties. Now go to Extended and under System performance on Settings. Now select the default setting For optimum display customize and then deactivate only one entry in the list:

Here you must deactivate the entry Show or hide menus in view

If this has not worked, you will need to try the Adjust for optimum performance setting.

NOTE FOR NEW PUBLICATION: This article was produced by Sandro Villinger and comes from the Windows Tweaks archive, which has been built up since the late 1990s.

Founded Windows Tweaks as a teenager in the 90s. His helpful PC tricks made it Germany's most visited Windows site (at the time Sandro looked like this). He then went on to write elsewhere, for example for PC-Praxis, Computer Bild and PCWorld in the USA. Microsoft also poached him from us. Now Sandro is back, finally sharing his tweaks here again. For a stress-free digital everyday life. You can reach Sandro via e-mail.

Leave a Reply

Your email address will not be published. Required fields are marked *

Windows Tweaks Logo Microsoft PC Help - 09 white 120
by Real Tech Experts
Save time and nerves with expert knowledge about software, hardware, AI & Microsoft. 
Windows Tweaks Microsoft PC Help - SINCE 1998 - retina 2

Time-saving tips for PCs, laptops, Windows and software?

Subscribe to our newsletter, receive only our best tutorials & tweaks and exclusive tips for our subscribers. 
Newsletter form
Can be canceled at any time. About 1 - 2 mails per month. The consent includes the information on revocation, shipping service provider and statistics according to our Privacy policy.
© 1998 - 2025 Windows-Tweaks.info
Made in Germany with ❤️ 
For all technology users around the globe.
This website runs on 🌳 GREEN energy
crossmenu
EN