Deploy .Cab Solution Webpart into sharepoint

(1) Open the command prompt
(2) Change the path to C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\bin
(3) run the stsadm command to deploy the cab file
stsadm -o addwppack -globalinstall -force -filename C:\SearchWebPart_CSharp.cab

(4) Go to sharepoint site's webpart gallery
(5) Go --> New and populate the webpart
(6) Add the webpart into your page :)