Hi,
Try the following - it assumes you're using either Windows 7 or Windows 8.
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 link below and save it to your Downloads folder.
http://ftp.hp.com/pub/softpaq/sp58501-59000/sp58919.exe
When the download has completed, open your Downloads folder, right click on the HPSA installer and select 'Run as Administrator' to start the installation.
After the installation, restart the PC again.
Regards,
DP-K