Also what would you keep/get rid of? If you could only change one thing about windows what would it be?
The thing I would want to do is make it more modular. separate kernel, user interface, system utilities etc. This would make open up more possibilities to interchange kernels, interfaces and hardware support and eliminate strange situations like not being able to remove IE. Granted, UNIX already does this, but I think that it is preferable to having one giant monolithic OS. It might be that this is a bit of a too fundamental a change. In that case, I would want to change the user interface. Make sure that the user interface can be interchanged with different UI's. This would make the time in windows way more tolerable.
The windows file explorer could really really be improved. The UI is a bad and it throws an error half the time when I try to copy anything.
Never had that problem to be honest. I personally miss the possibility to tab windows and to use 2 panes next to each other. Explorer++ does the tabbing (don't know about the panes), but given the fact that I spend most of my time in Arch anyway gives me little reason to install all kinds of little programs in Windows :P
remove metro. remove the need for such a large driver database upon installation - let me provide the drivers i want for even common hardware. make powershell the default interpreter and remove the limitation imposed by legacy shells - why should i need to call the powershell exe first to run a script in a scheduled task? it should work like .bat/.cmd files. get rid of all the different versions - one base install, everything else is an add-on that you choose to install - no only version x supports feature y, or upgrade to version z to get ab. im sure there is other stuff, but thats all i can think of at the moment.
Ah, the command line in windows. Isn't that something you should avoid at all costs?
nah its the only way to script things without writing vbscript <shudder>, which still uses the cscript or wscript executable interpreter. powershell is infinitely more powerful than batch, and much more user friendly and easier to troubleshoot than vbscript
I would take Direct X and make it POSIX compliant, so that it can be used on other OSes.