Well, for backtesting you want a desktop really. Although I used a laptop for that for a significant amount of time. Better to buy a good business-class laptop that is designed to work all day without any issues, seems like you've been buying crappy ones. Regarding CPU maxing out, you need to be aware what processes are running in the background, most people just install stuff that they don't need - task manager full of garbage.
You're not able to buy from Dell and pay to have shipped to Japan? Or does Dell have a "Dell Japan" and you have to buy from there?
Computers are kind of like cars -- if you take care of them and do basic maintenance...they can last forever.
Currently I have thirteen PCs going all with their own automation system, I don't want two systems on one machine, these machines are dedicated and some are five years old and one is 30 years old, had to have more AC placed into room cause in summer, like 175 degrees in there, I live desert community as it is, winters are nice, almost don't have to heat the house, LOL I just don't spend all the much time any more in my office, either in bed, Starbucks or somewhere else. Trading for me has become like something I feel I have to do to keep mind active. I been buying computers since 1986, I really don't see any difference for me at all between $2k laptop or $400 one, really don't, they either work or they don't. I have spent thousands on equipment techs said I had to have, and either they too tech for me or I mess them up. So I have a guy that comes in every Saturday and back ups everything, fixes problems, and that works better than high end equipment. You know yourself you hauling around the laptops and as careful as you try, you bang into something. Well when tech does clean install of Windows, then spends five hours on it trying to figure out why CPU maxing out and can't, he installed Windows 10 and all happy. I don't care what version it has as it is email laptop. My trading machines, one has charting and other has platform, neither have anything other on them except that, no games, movies, nada, they all have standard softwares to clean them of possible viruses, but since I don't surf, seldom ever have had those problems. I have laptops that stay at home and plugged into phone lines, then have the other ones that stay in travel cases, they have more security software on them. This arraignment has worked well for me past three years. You do what works for you is best for me.
31.4% discount on laptops and PC's in Microsoft store today only. http://www.ubergizmo.com/2016/03/microsoft-discounts-dell-xps-13-by-31-4-percent-for-pi-day/ http://www.microsoftstore.com/
There are big differences when it comes to laptops, from the materials used in production to chip quality, display quality, longevity etc. I bought an used bus. class ThinkPad myself and while it has had one problem that's more of an annoyance, I couldn't use cheap laptops as they feel trashy. A more expensive laptop can also take a beating, I've beat mine up with coffee cups and it doesn't even leave a scratch. A cheap Dell/HP would probably break into pieces. Not sure how good your tech guys are, I've had similar problems and have always been able to fix it. If nothing else, you don't allow the CPU hog of a process to start. But you do what's best for you. To me it sounds like a horribly cumbersome and badly optimized way of doing things.
Well, I buy some twenty laptops a year, I have staff that trade my accounts, they trade off reg PCs but have laptops as backups. As I said, I spent am sure over 100 grand in equipment in all past years. Staff can order what they want that makes them happy-those be replaced in three years, but bottom line, if you can trade, you can use just about anything these days. Computers annoy me now, LOL, don't like many things when you get older. I am getting at age where I just see things differently, hard to explain, but in some ways bit eccentric of maintaining a 30 year computer but that one has 500 gig HD, still runs under 286, but system I run I programmed on the old 5.25 floppies in basic. Just shows it don't have to be complex to be profitable. LOL, I have one computer where the case is made out of 2x4s, I bought it for cheap from a trader who smashed the case, runs great with added fans. The nice thing about cheap laptops is when you get really pissed, you can fling that sucker like a Frisbee till it hits the rock wall.
I use an ASUS G75V to run a CAD program. It has a nifty feature that allows one to easily clean the fan. It is also sturdy. The problem is it feels like it weighs 25 lbs.