Why does my computer slow down sometimes?
The most likely reason is that there are too many applications and programmes running at the same time. Usually closing down a few applications will speed things up. You may have unseen programmes, such as anti-virus software, running in the background. Check your system tray (in Windows, this is in the lower left-hand corner) to see if you have any programmes running in the background. A slow computer may also be infected with a computer virus.
Why does my computer screen go off while I'm working?