One of the worst problems in a computer is that, with usage, it starts running slow.
A computer running slow is not only a nuisance, it also hampers speedy delivery of work that is time bound and has a money value attached to it.
Try implementing the following and you are sure to see a dramatic increase in your computer speed:

1. Clean up your temporary internet files regularly.
   This can be done easily.
   Go to the Tools option on the Explorer bar.
   Scroll down to the Internet option.
   Click on the General tab and click on the Delete tab under Browsing History.
   
2. Go to the Content tab and click on 'Auto Complete Settings'.
   Delete Auto complete history and click on Ok.
   Now there will be no immediate complaints of computer running slow.
   
3. Run a registry clean up.
   This will delete all discarded and trash registry entries.
   This is better done if you have a good registry cleaner in the computer.
   
4. Switch on the Defrag option.
   Click on the Start button.
   Point your cursor to the Programs tab and mouse over the Accessories Tab.
   From here, click on Disk Defragmenter.
   The defragmentation process will take some time since it will defragment all fragmented clusters and files.
   There would be jump in the speed of your computer performance after the defragmentation is completed.
   
5. Try to upgrade your RAM to a better capacity one.
   Computer running slow problems are more due to low capacity RAMs.
   Gone are the days of 256MB RAMs.
   Try going in for a 1GB RAM so that your computer can access many programs at the same time and this will speed up your computer.
   

Now you will not have any issues with computer running slow.
The above procedure will help in increasing the speed of your computer.
Finally, if you have abandoned some programs, use the 'add /remove programs' option from the control panel and uninstall these programs completely.
This would free up more space to let your computer function with speed and efficiency.