Hi. Yes, if you go to Control panel/Programs and features, or add/remove programs (depending on which version of windows you have)
you will find a list of all installed software and also a list of windows updates.
Yes, the control panel will tell you everything currently installed, but sometimes programs that have been uninstalled leave little bits behind like a folder in 'c rogram Files' or entries in the registry.
If you provide more details on why you asked the question we can provide better answers.