Hi everybody!
I wrote a simple Windows shell script that makes a new vanilla installation of KSP by making hardlinks to an existing KSP directory. This allows you to have multiple installations without actually having to install it multiple times. I use this to have multiple sets of mods without actually installing KSP multiple times. It works well for me.
It is designed to be run from the command line. Due to its use of mklink, it needs administrator privileges.
Here is the code for it (spoiler-ed because it is kind of long):
To use this script:
Copy the code in the spoiler above.
Paste into a text editor, like Notepad.
Save the file with whatever name you want, wherever you want. Select "all file types" and change the part that says ".txt" to ".bat"
Open an administrator command prompt.
Navigate to where you saved the file using "cd"
Type the name of the file. Then, type the location of the KSP installation you are copying (i.e. "C:\Kerbal Space Program"). If this contains spaces, it must be in quotes. Finish the command with the folder of the new KSP installation. Type /? after the name of the file for help.
You should now have a second KSP installation, that has no mods.
Feel free to modify and distribute this code as you see fit. I'm not super experienced with batch files (I mostly use Python), so any input is appreciated!