I have an old Dell Dimension 4500 running Windows XP Pro SP2. Every 10 or so minutes, it pauses a few seconds, eg the nice lady says "you have e- ... mail" and so on. Rob Jones
This could be a hardware conflict or an interruption from a background task or, indeed, almost anything. Look in XP's Event Viewer utility, which you can find in the Control Panel's Administrative Tools folder. The Event Viewer tells you what your PC has been up to, and keeps a record of application faults. If you double-click an entry, full details will be on the property sheet. For more details, see article 308427 at support.microsoft.com.
If that doesn't find the problem, go to Start, select Run, type perfmon in the box and click OK. This runs XP's Performance Monitor utility, which will let you see what's happening. Running SysInternals' Process Explorer is an even better idea.