What are the system specs of the machine? Do you have any anti-virus or security suites that boot up and scan when started.
Click start > run > type msconfig > click startup tab
These are all the components that start up with Windows when booted. Remove any unnecessary items that do not need to be in here. Examples would be Itues, Real Player, WeatherBug.
Also if you are not comfortable removing these download Hijack this:
Trend Micro HijackThis - Free software downloads and reviews - CNET Download.com
copy and paste the log in here and we can help you pinpoint what is useful and what is not.