>I have a Windows 8.1 Pro tablet - but it has a rather small SSD card built into it. Luckly I have a 128gig SD micro card for it. So now I want to install Visual Studio 2015 on it. Problem is when I try to select my SD Micro Card drive (d:\) - it tells me that I can not install VS 2015 to removable media. I haven't tried to install nay other versions of Visual Studio yet. So is there a work-around for this? Is there some kind of hack I can do to let the install go to my micro sd card???

A wild guess - you could try SUBST at the command line to create a new drive letter e.g.

SUBST V: D:\

* or maybe create a share on the SD card and map a drive letter to it e.g.
NET USE V: \\TabletName\ShareName

I don't know how V: drive would be treated in either case. SUBST is quick to test, NET USE would take a little longer to set up.