"Jimmy Wilkinson Knife" wrote in message
news
How much memory do you have and what percentage is in use in the task
manager when it's slow?

6 GB (increased from the 4 GB that it came with). CPU usage is around
90-100% when the PC slows down, even though after the initial high usage
after rebooting it normally stablises to about 10-20%. It's often simple
things like redrawing the screen when a window is moved, or when a
background window is clicked to bring it to the foreground.

What tasks are using the 100% CPU?

Often it's a generic process such as system or svchost, so nothing obvious
that points to a process that has been explicitly started by the user or by
one of the various auto-start-at-boot mechanisms such as
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run .