|Chances are that you've got way too many things running in the background. Press "Ctrl", "Alt", and "Del" (otherwise known as the 3 fingered salute) to bring up the Task Manager, and click on the "Processes" tab. How many processes do you see in the list? Any more than about 25-30 is way too many. With Firefox running, I have a total of 21 processes in the list.|
Many programs are set by default to start when Windows boots, e.g. MSN Messenger, et al. To stop these programs starting at boot, you'll need to check the settings of each program.
By default, Windows starts a few unneeded services/processes on boot. While some users may need these, most don't. Go to the Black Viper Service Configuration site (Google for it), and follow the recommendations in the "Safe" column.
You can also click Start > Run, and type in "msconfig" (no quotes) and click OK. Click the "Startup" tab and disable anything that isn't needed. All you really need in there is anti-virus and firewall. To clean up the list, Google for "MSCONFIG CLEANUP", a free utility. Run it to remove unwanted entries in your "Startup" tab.
Also, download and install CCleaner, and use it regularly. It's a freeware program that will help to keep your machine free of unwanted temporary files and other junk. It also includes a non-aggressive registry cleaner (the only one I've ever fully trusted). I use CCleaner once a week, minimum.
Try these suggestions, and let us know if they have helped.
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