Click "Start" then "Run".

Type "msconfig" in the "Open" box.

Click on the "Startup" tab.

These are all of the programs that start to run whenever you boot up your computer. The fewer programs that are checked, the faster your computer will run. To determine if a certain program needs to be running, type the name of the program into google. I chose Omnipage SE for an example.

In the search results you will probably find some web site that will describe the program, like this one:

Read about the program and determine whether you want to have it running or not. In this example, I found that Omnipage SE has to do with my scanner so I decide to leave it checked.

Go through the same procedure for other programs in the Startup list. If you cannot determine what the program does then I do not recommend that you turn it off.