Xp will not allow program installation because of permissions

I am trying to install LivePerson Chat Applet on XP, current and updated. (if that matters.)

The machine has One User, who is the admin and has full controls and permissions as far as set up is concerned. When we install the LP software it installs and when clicked to open it pops an error that says:

"You do not have access to make the required configuration modifications. Please rerun the installation from an administrators account"

When we select "Ok" it completes the install and loads the application on the desktop. However the application is frozen, you can see it running, you can see people on the site through the tracking portion of the software but you cannot access anything on the applet window. Not even the "X", everything is frozen. You must close the application from the task bar.

I have spent 2 hours with TS at live person, we have installed, uninstalled, rebooted, changed permissions, etc. etc. etc. He came to the conclusion after logging into my machine that it was a PC issue, not their software.

Does anyone have any input on how to correct this issue. Tech support for XP is some ridiculous amount of money, so any help would be greatly appreciated.

Thank you
Dan