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It's critical that a computer object in Active Directory is placed in the proper OU, or it will not receive the correct GPOs. This should be the first step in troubleshooting a Group Policy issue.
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A second way to troubleshoot GPO issues is to open a command prompt and force Group Policy to update by typing:
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A third way is through the Event Viewer. Open the Event Viewer and navigate to Applications and Services Logs, Microsoft, Windows, Group Policy, Operational. The messages in this log can be very helpful. Further, if you right-click on Operational, you can save the log to a file and attach it to a ticket.
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General steps to follow when troubleshooting Windows network drive mapping issues:
Is the user account in the right Active Directory groups that give access?
AD groups grant access (NTFS permissions)
AD groups are used by Group Policy to map the drive
These groups might be different in some cases - ensure proper memberships
Is there an event in the Application Event Log that explains what is happening?
Successful and failed events are recorded
Use Event Viewer to look for an event
No event often means not in the AD groups
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groups
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The Windows Helper App includes some basic drive mapping troubleshooting help:
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