Since a full Windows reinstall did not fix it, the next most likely causes in this scenario are a driver/display issue, an incompatible app, or a recent Windows change that introduced a compatibility problem.
- Check whether the flicker points to the display driver or an app.
- Open Task Manager with Ctrl + Shift + Esc.
- If Task Manager also flickers, the display driver is the likely cause.
- If Task Manager does not flicker while the rest of the screen does, an incompatible app is the likely cause.
- Reset the graphics driver once to test for a display stack issue.
- Press Windows logo key + Ctrl + Shift + B.
- If that does not help, restart the PC.
- If Task Manager flickers, focus on the display driver path.
- Open Device Manager from the Start button.
- Look for any device with an exclamation mark.
- For affected devices, select Update driver.
- If a recent driver change triggered the issue, disabling or uninstalling the device is also listed as a troubleshooting step.
- If Task Manager does not flicker, test for an incompatible app.
- Since the issue remained after reinstalling Windows and only a small number of apps were added back, test those first.
- Go to Start > Settings > Apps > Installed apps.
- Uninstall Dropbox first, restart, and test file opening, right-click menus, and app launches.
- If the issue remains, uninstall Revit LT 2017, restart, and test again.
- This is especially relevant because the symptoms include screen flashing and slow app transitions, which Microsoft documents as a possible sign of an incompatible app.
- Check for stop-code style instability basics even if there is no blue screen.
- Remove any newly attached hardware if present.
- Make sure there is still sufficient free disk space; 10% to 15% free space is a good target, and the current free space already exceeds that.
- Install the latest Windows updates from Start > Settings > Windows Update.
- If the slowdown started suddenly in the week of Aug. 31 and everything was normal before that, use System Restore if a restore point exists.
- Microsoft Q&A guidance for similar post-update slow startup cases recommends restoring the PC to a point when it was working properly.
- Microsoft’s Windows troubleshooting guidance also lists restoring Windows 11 with a restore point as a next step when basic troubleshooting does not resolve the issue.
- If Windows Update itself seems suspect, advanced reset steps exist, but they are higher risk and require admin command-line work.
- Microsoft warns these steps are only for users comfortable with the command line.
- They include stopping Windows Update services, renaming the SoftwareDistribution and Catroot2 folders, then restarting the services.
- Use this only if update-related corruption is strongly suspected.
- If the machine is running hot during these delays, let it cool and test while plugged in.
- Surface guidance specifically notes overheating and memory-intensive apps can cause major slowdowns; the same basic check is still useful here.
Given the details provided, the best next end-to-end path is:
- Use Task Manager flicker behavior to separate driver vs app.
- Reset the graphics driver with Win + Ctrl + Shift + B.
- In Device Manager, check for warning icons and update or remove the affected display device if present.
- Uninstall Dropbox and test.
- If still slow, uninstall Revit LT 2017 and test.
- If the issue began after a Windows change and restore points exist, run System Restore.
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