So almost all energy consumed by a PC is dissipated as heat? Yes. The other forms of energy leaving your PC range from tiny to infintesimal: light from the ke

So almost all energy consumed by a PC is dissipated as heat? Yes. The other forms of energy leaving your PC range from tiny to infintesimal: light from the keyboard/case LEDs, kinetic energy in the exhaust air molecules, radiated RF (both intentional like WiFi and unintentional), radiated sound (both intentional from inbuilt speakers or connected headphones and unintentional from vibrating components), earth leakage, and resistance losses in external wired network connections. Most of these forms are then reabsorbed and converted to heat by other objects in the immediate surroundings as well. Increases in the energy stored within the PC are entirely dominated by temperature increases (which will equalise with the surroundings over time). There would also be a truly infintesimal amount of energy stored in changed potential energy in magnetic domains on your hard disk or stored charges in your SSD.