Do I have Windows XP Service Pack 2 installed ?

You can determine your Service Pack level using different methods:
Click Start, Run and type Winver and press Enter. The following screen appears which shows the Service Pack level of your system. If the words Service Pack 2 is present at the end of the line, then you have Windows XP SP2 installed.
Alternately, you can check the version information in the System Properties sheet. Right-click My Computer icon in the Desktop, and choose Properties. The System tab should display the Operating System, and the Service Pack level of your installation.
Or, type MSINFO32 in Start, Run dialog. The System Summary sheet should display the information that you need.