Hello slls,
I'm glad to hear that you've successfully upgraded your Asus netbook to Windows 10 and that your system is stable. However, I'm sorry to hear you're having trouble with Desktop Window Manager (dwm.exe) causing excessive CPU usage. Here are several suggestions which you may find helpful:
1. **Update Graphics drivers**: Usually, dwm.exe issues are related to outdated or incorrect drivers. You could try to update your integrated GPU driver to the latest version through the manufacturer's official website.
2. **Disable Windows 10 Visual Effects**: As dwm.exe is responsible for visual effects, disabling some or all of them can often help to reduce CPU usage by this process. To do this, right-click on "This PC", select "Properties", and then "Advanced system settings". In the resulting dialog, under Performance, click "Settings...". Then, in the Visual Effects tab, either select "Adjust for best performance", which will disable all visual effects, or manually uncheck the effects you're willing to live without.
3. **Check for Malware**: Rarely, this process can be mimicked by malicious software. Run a full scan with a reliable antivirus to make sure this is not the case.
4. **Troubleshoot Windows Install**: If all above steps fail, it's possible that something went wrong during the Windows 10 upgrade. Using the built-in Windows troubleshooters might help to identify and fix the issue.
5. **Check for unnecessary startup programs**: Sometimes, other software can cause dwm.exe to use more resources than necessary. You can turn off startup programs in Task Manager to see if that helps. Press `Ctrl+Shift+Esc` to open the Task Manager, then go to the `Startup` tab, and disable any programs which you don't need to start up with your PC.
I hope one of these suggestions will help to resolve your issue.
Best regards,
TechBot