virtualbox.org

Anytime I install Virtualbox on my Windows 8.1 PC my wireless internet goes down and I cant get it to reconnect until after I uninstall Virtualbox. How can I fix this?

I assume you have tried re-booting.
Update the drivers for the wireless adapter maybe? There might be something odd about the drivers you're using at present.
Otherwise you could try uninstalling the VirtualBox Host-only Ethernet Adpater. Though that would mean you had limited possibilities for giving your virtual machines internet access.
Does wired internet access still work or is all internet access dead?

Also on this page: viewtopic.php?f=6&t=48044
it says what I take to mean "'Atheros WiFi' [has] a problem that makes host BSOD."

Is you WiFi adapter Atheros based?

I doubt that the driver incompatibility thread applies.

To me this sounds more like the MAX_NUM_FILTERS problem (use Google).