First try what is suggested by BabaChazz in his comment above and is what most Hams would do to start. Listen for the noise on an AM radio. You do not want FM, as one of the characteristics of FM is to block this noise.
Take your (preferably hand-held) radio and tune it somewhere on the dial where there is no station. Then, you can try moving it around your computer to hear all of the RF interference your motherboard, etc. are giving off. If you cannot hear this noise, something is wrong with the radio--be sure it is set to AM. :-)
Leave the radio on, and you might hear the noise start at the time your WiFi drops. If you do not, the interference is not covering the AM frequencies (an arc will cover everything), and it is probably time to call in a Ham.
It is likely you will hear it.
If you hear it, you can walk around inside and outside your house listening for where the noise gets stronger. Often this will be tracked down to a phone pole or something else.
Once you find it, contact the appropriate person (electric distribution supplier, city, etc.) Convincing someone to fix a problem like this is not always easy.