If you find that your Libraries folder in Windows 7 opens on startup, then you may want to try some of these troubleshooting steps. These are just of the things which come to my mind and you may try them in any order you wish.
Windows 7 Libraries folder opens at startup
1. Check the Start up folder located at C:\Users\username\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup. See if you have by mistake placed the shortcut of the Libraries folder there.
2. Type msconfig in start search and hit Enter to open the System Configuration Utility. Check if disabling any entries help you. Check the path of those entries. If you see any dll file with startup path from “%localappdata% or C:\Users\Username\AppData\Local disable it and see if it helps.
3. Open Control Panel\All Control Panel Items\Troubleshooting and click on Check for performance issues to open the Performance Troubleshooter. Run it and have a look at its suggestions. Maybe it will indicate some problem or show a startup entry which you may want to disable; especially if the startup path is C:\Users\Username\AppData\Local.
4. Re-register Shell32.dll and see if that helps. Shell32.dll stores information about Windows interface and is used to open files and Web pages. Type regsvr32 /i shell32.dll in start search and hit Enter. The /i switch stands for install. Restart the computer. Read more on how to re-register dll here.
5. Run the Windows Explorer, File and Folder Troubleshooter ATS from Microsoft.
6. Try a system restore to a prior point, and see if it helps.
7. Run sfc /scannow and see if it helps. You may have to restart your computer after it finishes the job.
8. If nothing helps, you may have to try a Windows 7 Repair Install.
Hope something helps!
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