How can I uninstall a Custom Webpart from Sharepoint Server 2010?
Thanks
Use PowerShell commands to add/remove or upgrade solution///
Adding Solution
Add-SPSolution PATH
Deploying solution
Install-SPSolution SolutionPackage.wsp –WebApplication servername –GACDeployment
Uninstalling solution
Uninstall-SPSolution SolutionPackage.wsp –WebApplication servername
Removing solution
Remove-SPSolution SolutionPackage.wsp
Install-SPSolution –Identity $solutionName -Webapplication $webapplication -GACdeployment
I would like to add link related with the question. Beytan Kurt is right but if you try to add a new web part in your page you will notice there in the Category section it still have reference to the web part. This link which I post it will give you a full explanation why the web part still have reference into Category section. Also it will help you to fully remove the web part from your farm solution. This is the link .
Best Regards,
Stefan Chonov
I was unable to retract solution both by Central Administration and by Power Shell due the following error:
Uninstall-SPSolution : Admin SVC must be running in order to create deployment timer job.
The retract was being scheduled but not executed at all.
So, I opened the SharePoint Power Shell as administrator and typed the following command after schedule my retract:
stsadm.exe -o execadmsvcjobs
This command force all the admin scheduled jobs to be executed, so the retract worked good. It works for install and uninstall a web part. Good luck.