D.I.Y Modifications:
Installing a Halogen Lamp into PC
This story is told in pictures, as pictures say a thousand words, this is an essay:

Here we can see the setup, inside the old PC. The Lamp stands vertically up the case leaning slightly aft to avoid the Power supply and reaches just above the old hard drive slots to fit perfectly in at the top.

Here be the lamp head avec bulb that shall will be letting me bask in it's artificial light for the weeks to come, maybe months.

Here we can see a birds-eye view of the beast in action. Once the case is closed a shaft is created from which no light can escape, creating a tunnel light effect casting a perfect enlarged rectangle on the wall.
This picture prooves that a floppy disk drive does still remain in the system - it is about the only removable thing not yet removed. But this picture also shows my shoddy D.I.Y skills and use of sellotape to stick the wire to the case so it doesn't 'flap in the wind'.. or whatever.

Admire the flowing fortress of death my pretties...

Here the camera took 23 seconds to adjust to the brightness of the light to avoid an all-white picture.

Overall I'd say I learnt alot from my D.I.Y adventure, that you can indeed install a halogen lamp inside your old PC but that it is rather pointless however has small novelty value so it shall stay. It could be rather useful as a massive torch, but mass is high and portability is low so
it is not recommended, but if you do try it - we want pictures.