No. There is no possible upgrade for a computer with a 120 MHz Pentium to an 800 MHz processor. You couldn't even replace the motherboard, as the case would not support newer motherboards (AT/Baby AT vs. ATX/microATX)
To laugh at him
Intel.
Yes
Pentium Duo Quad, Pentium core duo, Pentium D, Xeon, Itanium, Pentium M, Pentium 4, Celeron, Pentium 3, Pentium 2, Pentium Pro, 486, 386, 286.
Pentium 4 with HT technology runs at the highest speed.
Yes, but it must be with one of the same type. EG, you can swap an Intel Pentium 3 1.5GHz with a Intel Pentium 3 2GHz, but not with an Intel Pentium 4 2GHz. Also, it must be the same socket type.
Before the Pentium CPU was introduced, the most common cooling mechanism inside a computer was a simple fan that was typically attached to the power supply.
Pentium 4
About 1 Gram
It's limited by your motherboard on what CPU it can take. The list of supported processors is most likely listed in the manual.
The Pentium 4 got it's name because it was the next series of Intel's flagship CPU line after the Pentium III.
Pentium D was the first dual-core cpu.