To deploy the Web Part by using Windows PowerShell

1- On the Start menu, click All Programs.

2 - Click Microsoft SharePoint 2010 Products.

3 - Click SharePoint 2010 Management Shell.

4 - At the Windows PowerShell command prompt (PS C:\>), type the following command, and then press ENTER:

      Install-SPWebPartPack -LiteralPath "<PathToCabFile>" -Name "<WebPartName>"

Where:
   <PathToCabFile> is the full path to the CAB file that is being deployed.
   <WebPartName> is the name of the Web Part that is being deployed.