why disable virus scan when installing android sdk - won't it render the computer vulnerable during that window?

Answer 1

First of all, this is not compulsory to disable antivirus for the installation. The recommendation is "just in case". Antivirus can block access to some files and it may affect the installation process. Antivirus app itself might be using some libraries that are going to be updated during the installation process, so you don't want anything "holding" them either.

The funny thing is - if you install something NEW to your computer/device you really want your AV to be ON to check what is being installed (for security reasons).

Answer 2

Well the SDK does a fair bit of interaction with loads of other programs and may run automated scripts. Scripts which most antivirus consider to be malwares. So just to be cautious it is advised to turn off your AV.

I have also seen AV's block connection to internet, now most prompt action to allow the program to connect to the internet, but just in-case you have notifications disabled, well you are going to have a hard time figuring out why is your SDK not working. So its "advisable" to turn off your AV.