It appears like there is a program which is starting up when the computer is idle.. Maybe an antivirus or scanner of some sort, but to assure that things are running correctly,,,,
First, take the cover off the computer and use compressed air to blow out all the dust from around the processor, heatsink, the power supply, and all fans and vents.
Next, turn off any screensaver you might have running. Likewise, disable Standby and Hibernation from the Control Panel-Display-Screensaver tab-Power button.
Next, uninstall any programs that you don't use, and because the problem you're seeing could be the result of too many programs running in the background, or conflicting programs running in the background, please disable unneeded startup services and programs using Start-Run, type "msconfig", click on OK, then click on the "Startup" tab.. Uncheck any items that aren't required to run at startup. Likewise, if you've got more than one antivirus installed on the computer, keep just one, and uninstall the others.
Next, download, install, and run a full system scan with the malware removal tool from the link below:
Malwarebytes Antimalware
Hope this helps and let us know how it goes.
Grif
Recently i have encountered a problem when i leave my computer idling for a while (five or more minutes).... the desktop icons lock up, and when i put my mouse over the taskbar, the hourglass appears... also, when the computer locks up, there is a new icon in the taskbar that looks like a computer monitor... anyone have any ideas?

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