SP 2 slowdown and wireless problems

Two of my systems have been updated, and both load dramatically slower on
startup.... perhaps 4-5 times slower.

Also, my computers'ability to sign onto my wireless network is crippled....
I must power down and up repeatedly and then it drops off the network after
an hour or two.

What's happened and what's the fix? Things used to work fine for me on both
of the systems.