This guide isn't mine but I thought you guys may find it slightly helpful. NOTE: this is VERY basic stuff. So don't get angry Enjoy!
Tip #1 ? Upgrade your memory. Most users will see a distinct improvement in performance when they add more memory. You?ll need to consult the vendor or the manual to know what sort of memory to buy but sites such as Crucial Technology http://www.crucial.com/uk/index.asp will give you all the information you?ll need. With prices around ?36 for a 256MB 168-pin DIMM, you can afford to be generous. See Tip #10 for information about how to understand your system resource loading.
Tip #2 ? Clean your desktop. All those icons on the desktop can slow your system. You can safely delete icons that run programs by selecting one or more and pressing the delete key. Get into the habit of running programs from the Start Programs menu instead. XP users have a Desktop Cleanup Wizard to help them clean their desktop ? it?s to be found in Control Panel, Display, Desktop, Customize Desktop.
Tip #3 ? Clean out unwanted programs. You have probably downloaded and installed several programs you no longer need. Like spring-cleaning your kitchen cupboard, you should clear out the rubbish. There is only one safe way to do this ? use the Add/Remove programs utility in Control Panel. Never try deleting folders directly.
Disk Cleanup wizardTip #4 ? Clean out files no longer required. Your system is full of unneeded backup, log files and temporary files ? why not clean them out to create some disk space? The Disk Cleanup Wizard will do all this and will empty the Recycle bin as well. Just select Start Menu, Programs, Accessories, System Tools, Disk Cleanup. This great wizard calculates how much space you?ll save, and allows you to delete files by category. From the screen shot here, you can see that it will free a massive 23MB of disk space on my system.
Tip #5 ? Defragment your hard disk. Now you?ve freed up lots of disk space, the next step is to defragment your hard disk. As you write to your hard disk, it becomes more and more difficult to keep files stored together so a file may be split or fragmented, over several parts of the disk. This slows access to the files, causing the system to slow. Select Start Menu, Programs, Accessories, System Tools, Disk Defragmenter. Remember to disable any screen savers before defragmenting or it?ll never finish.
Tip #6 ? Use a decent Antivirus tool. Viruses can slow your system quite significantly as well as cause damage to files. Use an Antivirus tool such as the free AVG which can be downloaded from <here>. Be sure to update the virus signatures regularly.
Tip #7 - Get rid of screen savers ? they are not necessary and occupy resources.
Tip #8 ? Don?t always rush to use the latest bloated software. For example, Office XP may have lots of bells and whistles but it?s slower than the leaner versions of yesteryear.
Tip #Windows Task Manager9 ? Be sure to use the latest drivers. Manufacturers often update the driver programs for your system components eg. for your graphics card. To identify the component use Control Panel, System, Hardware, Device Manager. To find the latest driver search on the component name using a good search engine such as www.google.com.
Tip #10 ? Understand your system loading. The most common reason a Windows system slows down is when you?ve used every byte of physical memory (RAM) and Windows has to start paging which is to use your hard disk as extra virtual memory. As hard disk is much slower than physical memory your system will slow down. Knowing how close you are to paging will tell you whether you need more memory. With Windows XP, just press control, alt and delete keys together to start the Windows Task Manager. Do you see the Commit Charge at the bottom right corner? The first number is the total amount of physical and virtual memory in use. The second number is the total available. If the amount in use is greater than half the amount available, it may be time to increase the amount of memory on board.
Skyty's Tip - Go to Start, then Run, type in msconfig on the tabs at the top got to the one called StartUp disable any useless things that are enabled. Hit apply then restart the computer.
Yet another tip I found. I don't know much about it but it's called TinyXP normal XP Pro takes up 1.1 Gigabytes and TinyXP only takes up 390MB! It will also run on 40MB or RAM!