There's a possibility that your Windows XP isn't up to date with updates. Try updating your Windows XP with all windows updates, then restart after the last updates. Often after updating and restarting, more updates will become available. Continue updating until no updates are available. Also, antivirus, antispyware, and firewall programs can cause havoc to program installations. Try disabling these programs during the installation. After the installation, run the program once to activate it with the serial key. Then after the program is activated, close everything, restart, and it should be fine.