can't unstill, can't reinstall, nothing happens

Dear people,

I've been using the 32 bit version with out any problems, then today it told me it's about to expire so I should install updates, which I downloaded. Then when I tried to install them, absolutely nothing happened. (Repeating the process, again nothing). I can't uninstall the old version either (can't see how).

My OS is XP Professional.

Can anyone help me with this?

As with any program you can uninstall it through the Control Panel -> Add/Remove Programs dialog. Then you can install the latest version from