Hi,
Try the following
First of all, uninstall your current version of HP Support Assistant by using the Microsoft 'Fixit' on the following link - this is particularly useful in correcting issues that may prevent reinstallation on machines running a 64bit OS.
http://support.microsoft.com/mats/Program_Install_and_Uninstall
When this has completed, restart the PC.
Next download and install the latest version of HP Support Assistant from the page on the link below - the download links are towards the bottom of the page.
http://h18021.www1.hp.com/helpandsupport/hp-support-assistant.html
After the installation, restart the PC again.
Regards,
DP-K