Secunia has released a beta version of a software inspector tool that checks to see if your system has the latest versions of Flash, Java etc. It also lists much of the other software installed on your computer.

Installing the program puts a shortcut in the 'Startup' folder so that it starts with Windows and puts an icon in the SysTray. I'd suggest the program doesn't need to be monitoring constantly and the shortcut can be removed. Perhaps just start the program manually from time to time and press the program's 'Scan Now' option.

https://psi.secunia.com/