|Lots of things can cause Windows to run slower that have nothing to do with the ram performance. |
If you do not have enough free space on the hard drive partition Windows is installed on, Windows will slow down considerably.
What size is your C partition (logical drive) , and how much free space is left on it ?
Have you installed Windows from scratch since the performance was okay ?
If so, your computer will probably NOT perform as it should until AFTER the main chipset drivers have been installed for the mboard.
"....I have rechecked msconfig & removed unwanted startup programs...."
De-selecting lines in the Startup list does not remove the program, but it does disable the program from loading, if the same enabled line does not re-appear on it's own.
Some lines load on their own again because they're not dependant on only that line being enabled.
There are many things that could be loading that can slow down the performance of Windows that don't appear in the Startup list.
Some anti-malware programs that have resident modules that run all the time in the background are known to slow down the performance of Windows more than others.
Which anti-malware programs(s) are you using ?
By the way, you should never have more than one anti-malware program installed on your computer that does the same thing (or more than one third party firewall) that has one or more resident modules running at the same time, unless you disable the the resident module(s) in all but one program.
Some anti-malware programs are scheduled to do a full scan of your system in the background by default when you install them, at a certain time once a week, or even at a certain time once a day. That always bogs down Windows while it is running. If the computer was off at the scheduled time, most programs will run the full scan right after the next time you boot the computer.
Windows MediaPlayer 10 and 11 have a feature where you can enable sharing your media. Don't enable that. If you do, there will be a program that will be running much of the time that slows down Windows.
You can add a feature to XP called Windows Search (Windows Desktop Search). It appears when you search for something in XP in My Computer or Windows Explorer instead of the default search interface. It's supposed to speed up searches by making indexes of files on your computer, and it's supposed to make those indexes after a certain period of inactivity by the user, but the problem with it is, once it starts doing that, it does NOT stop doing that when the user resumes actively using the computer, and it noticable slows down Windows when it's running. If you have installed that, I strongly suggest that you un-install it, in Control Panel - Add / Remove Programs.
Does the hard drive activity led stay on or blink for a long time after you boot the computer, e.g. for more than 5 minutes ?
If so, press Alt-Ctrl-Del to pop up Task Manager
Under the Processes tab, click on the CPU (activity) tab twice - that will dynamically list the programs with the ones that are using the most cpu time at the top - ignore the first entry - that's the available cpu activity.
Which programs are pigging out on the cpu activity ?