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How to Migrate MOSS 2007 to 2010
1. Take MOSS 2007 content DB backup
2. Create a DB in SQL Server and restore on it
3. Create a New Web Application in SP 2010
4. Central Admin > Manage Application >Manage Content Database > Select the specified DB
5. Select “Offline” and click on ok
6. repeat step 4 and select “Remove ContectDB “ Check Box >OK
7. Open Powershel and Use the following command
8. Mount-spcontentdatabase-Name “DBName” -WebApplication http://servername/webpallicationname
If You will get 403 error go to
Central Administration -> Application Management -> Configure Quotas and Locks
Set the Site Lock Information to "Not Lock" (it had been set to No Lock”)