You are may facing of this problem. Most of user that using computer or laptop may be facing this kind of problem. Your computer sometime take a long time to start the windows. Take a long time to process or doing multitasking job. Why all this kind happen? There are many posible of that.
1) Many Antivirus inside of your computer. Some user like using more than one antivirus. Maybe the reason os to keep protect thier computer. For the security is good but it make taking slow your computer to running application while you doing you multitasking job. Because every antivirus must be doing real time scanning. Real time scanning is hidden. That why you are suddenly prompt out when virus infected to your computer. The solution is : Please use only one Antivirus only. Do not forget to updated your antiviurs online.
2) Your computer is my be infected by Spyware. Spyware is the computer software that install automatically to your system. Normally it is a hiding job. You will not viewing this kind of process. It mostly coming from internte. As long as spyware keep inside you computer, it will take slow your computer as well. You can keep track all the spyware infected or activity by using the Anti-Spyware. For the free Anti-Spyware, i recommend your using Spybot. Keep update and doing the full scanning once a week.
3) Memory is not enough (RAM). Memory is the main thing that you should take care about it. Some people buying the computer without care about this. Your memory is must be enough you Operating System and all your application that you need to running on. Where to see you memory usage? Now a days minimum memory for Windows XP is 256MB. But i recommend you must be using 1GB RAM memory. Because when you start your windows include antivirus it will take almost 300MB from your Memory. If you using 1GB RAM memory your have spare 700MB more. This can use for all multitasking application for your work such Internet Explorer, Ms Outlook, Lotus Notes and so on. So if method number 1 and 2 is still not helping you, please take a look of this.
4) Your computer is must be loading a lot of application while starting up. Be carefull when you installing the software application. It might asking you to running this application while startup. I not recommend to you by running on all application that you are installing to your computer. The IMPORTANT application must be running on while startup is only your Antivirus all important servicess taht running on by Windows. You can disable all the application by running while startup is like this:
a) For Windows XP : Click Start –> RUN –> and type MSCONFIG
b) Go to Startup Tab and disable unnessary application that running while startup. Leave only your important application.(E.g : Antivirus, Networking Application etc).
c) Use another tool to disable unnessary application that loaded while startup (Recommended : Hijack Tool).
d) Then restart your computer and see the result.
Here the information that i can share with you. Use this method to increasing your computer speed and make you feel love to your computer and your work.