MacBookPro. Awful, awful. How do I get this issue of almost no internet resolved?

[Fatamorgana]

Around Xmas I loaded Yosemite.

Since then, bit by bit, meter by meter, my ability to pickup any given router has diminished such that if I am more than two meters away I can not do diidly squat.

Is it Yosemite 10.10.4? Coincidence?

How do I reload the previous version/ OS?

How do I hunt for a virus (?) if such a thing exists on these machines?

Mine is a 2012 / 13 model. Trash empty, 15% or more available on the HD. Anything else i need to be thinking about to speed things up? But really the issue is an almost inability to see any router I point it at.

Thanks.

 

[pigoo3]

Just so we know. Are other devices working ok with this router?

- Nick

 

[Fatamorgana]

Yes, various routers, various locations, various countries, various other users.

 

[pigoo3]

One thing you could try is running the free maintenance app called "Onyx":

http://www.titanium.free.fr/onyx.html

- Nick