Tips to improve Computer's Speed

1. Use software like c-cleaner which removes all of the unwanted temporary files and registries (which may occupy more than a gb if not removed for a long time).C-cleaner deletes around 10-20 mb each time i run it after finishing my browsing work.This can also fix issues and errors with system registry.It occupies only very less space (less than 2 mb).Hence i recommend that.

2.On installing a new software or a program (especially programs more than 300 mb) it is better to install them in a drive other than the drive with operating system files(usually C drive).This would make the hard disk to run minimum rpm to cover both OS and the software files with much higher efficiency.

3.Defragmenting the drives weekly once (or after installing a heavy software)will optimize your computer's performance.This can be done by ->right click a drive(eg: C) ->properties->tools->Defragment now.
You may also use other softwares like Disk Keeper to do the same.They will be much more informative than the one that comes with XP or Vista.

4.Always keep your My Documents folder with minimum number of files.Several softwares ,even after uninstalling leave unwanted temporary files, cookies etc. which not only occupies some space, but will also reduce your search efficiency ,because every search begins with My Documents.

5.Keeping track of statup programs will always be a good solution to improve speed.For eg, you may use Yahoo Messenger only if you are connected to the internet, but it may start everytime after booting and will be using up RAM staying idle in the taskbar. Hence the settings of these softwares must be changed according to our needs.

The above mentioned C-Cleaner will be a great help for this.Because you can select your startup programs all in a one screen.This can also disable some programs which doesn't have the option to disable at startup( eg:Nero monitor,Adobe speed launcher, etc).

The above mentioned steps will improve your computer's speed drastically without any external aid.