I see that the problem was resolved with a restore. Yes, sometimes the odd solutions are the simplest and best, especially when free.
As a Dell certified field tech, I see many similar issues, but AS a field tech, I am called to replace hardware parts after the help desk's software solutions didn't work. With 20 years of experience, I can say that one must try both, sometimes, to find the real solution.
The cases are engineered to optimum air flow while all the sides are on it. If it were more effective, the case would not come with a side at all. Air must be moved through the machine so the hot air, from the various internal heat generators, is removed as quickly as possible. With this, the PC or laptop acts as a mini vacuum, sucking in all the dog hair, food particles and lint from you pants/skirts, bedspread, couch and floor. Keep the PC at least 4 inches off the floor with the same amount of space front and rear, and use a lap desk for your laptop computer (something flat and hard)
Dust is a big enemy that leads to overheating. Keep the PC at least 4 inches off the floor, and blow out the dust with canned air, not with the compressor in the garage, which contains moisture. (On metal/electrical parts?) Never a vacuum cleaner, unless design for computer equipment, as regular devices generate a lot of static. Dust collects under the mobo, inside the power supply, on the system and CPU fan blades, and between the CPU fan and heat sink.
Of course, these are preventative measures for the hardware itself, and the list could go on.