>>>>>>>>I don't see why not. You can do that in Window's Disk Management. Personally I don't recommend more than two partitions; one for Windows ans applications, and one for data.
>>>>>>>
>>>>>>>I prefered to install, whenever the installer allows it, the apps somewhere else. Over the years it was usually some kind of mess which would force me to reinstall the windows. Either the whole C: drive would become a mess, or it would start losing IP address (XP was notorious with that), or the registry would get hosed... anything. Happened on the average every three years (sometimes twice in the same week). Having the apps somewhere else saved a lot of time. You wouldn't believe how many apps out there don't give a damn about the registry and use their own registration and settings, in plain old files in app folder. Or %appdata% when the app folder became a no-no. Having both of them somewhere else saved me days.
>>>>>>>
>>>>>>>In other words, D: drive is mine, C: is sacrificed to M$.
>>>>>>>
>>>>>>>Of course, I stopped doing that :). Happily living in Linux for four years now.
>>>>>>
>>>>>>Actually, I can't remember having a single problem with Windows for many years now. But then again, my memory isn't what it used to be. I don't think it ever was...
>>>>>
>>>>>Do you use Windows 10 or 7?
>>>>
>>>>10, and I have used it exclusively for many years now.
>>>
>>>I am buying Window 10. Hopefully I will have as good of the experience as you have had.
>>>Thank you.
>>
>>If you buy it, I recommend a clean install. It will take a few hours, but you end up with a much faster machine. I also recommend that you buy an external HD box, and use it for the old HD.
>
>I am not sure I understand the term "clean install" and the external HD. I am buying a brand new PC - Windows 10 - with a 1 TB drive. So, the manufacturer (Dell) will install Windows 10. I don't have an option for them not to install it. And I will still use the existing computer (Windows 7( with the 'old' HD (just in case).

If you get a computer that comes with the OS pre-installed, there is often additional software pre-installed. Often it's trial editions of software -- with the annoying behavior where the trial period runs out at an inopportune moment. Some software I immediately uninstall -- like McAfee Antivirus, Symantec Antivirus, Norton Antivirus...