:confused: when I download a program or install it and it takes awhile, and then asks to reboot(giving me the button to press to do that) it has a problem about doing that very thing especially when I say - walked away from the machine (while it was doing its install or checking) for 15 minutes or more. The reboot button supplied by the program does not function nor does anything else. My screen has locked up.
Why would it do that?
At other times when I am right there and the reboot question appears and I activate it immediately, it works.
A program that has this timer problem is SpybotS&D
Can I fix it?
As it is, when it locks up I got to pull the plug out to shut off my computer for the restart

To make sure everything is running fine run both anti virus and anti spyware apps in normal AND safe modes. (make sure that they are updated first ! ;)) (AVG (http://free.grisoft.com/doc/1) is good and free AV)
(A couple of good removal tools are Spybot (http://www.safer-networking.org/) and Adaware (http://www.lavasoftusa.com/software/adaware/))

ALso an on line virus and spyware scanner is Trend Housecall (http://housecall.trendmicro.com/)

Just a note; actively running two AV's on one machine can cause problems.
So if you are thinking about it make sure your current one is disabled first.
SAme thing applies to online scanners as well.

Removal of junk files is easy with CCleaner (http://www.ccleaner.com) a free app that does exactly what you need.
Part of CCleaner is an uninstaller, it is advisable to remove any programs that you are no longer using.
Also check to see what is loading at start up.
As a rule of thumb they only apps that should load on start up are security ( anti-virus) and connection apps.
Other start up apps are up to you, but if you don't use it all the time then make sure it doesn't load on start up.

In addition, I have had trouble using the SpyBot S&D Timer. Try disabling the Timer and see if that fixes your problem. Part of what SpyBot may do is prevent your install from being able to make the needed changes to your registry. It is protecting your registry from unauthorized changes. If SpyBot is malfunctioning it can create problems for your installs. SpyBot has an option to use or not use the Tea Timer.