Big performance drop after installing VBox

[Snkifador]

I'm having a weird issue with my VBox installations on a Windows host.

All I can notice is that my whole system becomes extremely slow after installing the software. This persists regardless of having the application running or not, and also regardless of having any VM up and running or not. By "slow" I mean that pretty much every other application works slowly. For example: swapping windows is delayed; video renders at extremely low FPS; loading from the HDD takes longer. Just a generally sluggish behaviour.

A year ago, the same happened and at the time the only thing I could do to fix it was rolling back to prior to installation (IIRC, the program wouldn't let me uninstall). This time around, I managed to uninstall and it solved the issue.

My specifications, in case they matter:
-Asus N56VZ;
-Windows 7 64bit;
-common Intel and Nvidia CPU/GPU (3630QM, GT650M);
-8GB DDR3 RAM;

Any input towards what this might be, or what other information is needed, is highly appreciated!

[mpack]

I don't like to speculate, and anyway there should be no need: open the host's tasklist and see directly where the problem is. I'm quite sure it will not be VirtualBox, despite the coincidence. It'll most likely be your Win7 host banging it's head against the VBox host-only adapter, trying to probe a non-existing "insecure" network connection. The host-only driver is about the only piece of VBox software that's active when VBox isn't running.