Many people use various methods to try to speed up their computer. There is also the option of deleting and recreating the user.
If you look into the Documents and Settings folder in XP or Users folder in Vista, you will find the various user names under it. If you enter the folder of a user, you will find that it contains various hidden and unhidden folders.
The folders that I am interested in is the hidden files Application Data and Local Settings. My application data folder is 86MB and the Local Setting folder is 2GB. This is unusually large.
When you create a new user account, you will see that the new account will have these folders but usually under 10MB each. Therefore, what are these folders for?
These folders contain information about the different programs that you have used. If you delete the programs and do not use them, the information is still stored under the user that has used them. This allows the user to store customizations to these programs for that user.
Therefore, if you are finding that the computer is still slow after doing the various methods that you find, try deleting and recreating the user. Remember to backup any files that you want to keep.
A better approach would be to create another account called David2, for example, that you will use instead. This will allow you to compare the speed of starting up each user. You will find that the new user starts up much faster.