I've gotten in the habit of carrying a light 24/7, next to my pepper spray. Not many people notice them, and my life is far too random to actually know where I'll be or when I'll be there.
If you want serious light out of it I can bore the body so it will fit a CR123 A and get L2D light out of it when you eed the extra lumens but a single AA L1D is not slouch.
Oh yeah, I carry the P3D daily, and like I said...its just as bright as the day I bought it and I make it a point to use it every single day without exception, and have done so...for about a month now I guess.
Its the best flashlight I've ever owned or used. It uses the CR123 batteries, I have 20 of them and 2 rechargeables with a recharger. I'm still using the 2 extras that came with another flashlight I got.
P3D is my formal recommendation. I use it on Turbo, 160 lumen, 100% of the time...for digging around in computers you could easily use the lowest setting and see what you're doing...and it would probably last you 6mo-1yr of daily use on that setting.
P3D in non-turbo mode defaults to the lowest light setting, which is easily bright enough to light a path in the woods...so definitely able to light up a computer box.
*We all love our lights, and they are all pretty damned sweet...so I think you're going to win with whichever one you choose.*
here is a link to where i get all of my lights. They are far less expensive, probably because they are the direct source in China. The items usually take about 2 weeks to come in, but I'm in no big rush if the trade off is significant $$$ savings.
they are VERY bright, and I accidentally made someone puke when i hit the strobe button by mistake, they saw it for only 3 seconds and they were done. (strobe was from one of the small black ones)