The following is a modified version of an older post of mine. All of the downloads are free and legal.
MSCONFIG (when used with the RUN command) opens up the System Configuration Utility. Most of the stuff in there you don't want to mess with unless you know what you are doing or have detailed instructions.
Click the STARTUP tab. The list that it pulls up is everything that you can choose to start up when Windows does.
Why is all of this stuff in the list? Because every program designer thinks his 'creation' is so indispensible that no one could possibly want it to NOT start up with their computer (yeah, right), so they set it into the list and have it to do just that.
Once you're at the list, look it over and see what all has a check mark. Every program that does starts up when Windows loads... EVERYTIME!
If something is checked, but you don't know what it is, Google it and find out.
Once you have seen what is there, uncheck everything that you don't need or want. Keep your firewall, antivirus, broadband drivers, graphics drivers, whatever you absolutely have to have, but uncheck everythign else.
Once you are done, click APPLY, OK, then reboot.
When your computer starts up, you'll get a grey box about the System Configuration Utility. Check the box about 'Don't run on startup' then OK.
If you had a lot of stuff checked, then your comp ought to start up faster and run more stable.
Download and run AdAware, Spybot, and possibly Microsoft Windows Defender.
(All are free. Be sure to have each one update itself before you scan.)
Uninstall any unused or unneeded programs you have on your hard drive.
Download and run TweakNow to clean up your computer's registry, and RegCompact to defrag it.
Run Disk Defragmenter START- ALL PROGRAMS- ACCESSORIES- SYSTEM TOOLS- DISK DEFRAGMENTER).
Reboot your computer and see if it cranks up a bit faster, plus it ought to have a lot more zip to it as well.