Ready boost and mobility center problem on windows 7

Hi there to everyone reading my post . I am a newbie to this forum and I need some help :-

1) on my viewsonic viewpad 10 tablet , it comes with windows 7 home premium . I have been able to use readyboost on w7 , recently I have update to w8 consumer preview and also able to use readyboost with my sandisk 4gb thumbdrive like before , but after a few times of shut down and boot up my w8 , now I cant use the same usb thumbdrive as readyboost , it say :- this computer is not enable to use readyboost because it is fast enough already ! I don't understand why I can use it the first few times and after that I cannot continue to use it again . Can any expert please help me out on this problem as I would very much like to run readyboost even though it speeds up just a little bit , I don't mind .

2) when in windows 7 , inside my mobility center ,there is a switch for WiFi on and off . But after I installed windows 8 , inside my mobility center , the whole WiFi box is missing , there is no more WiFi on/off switch there ! Is there any way to set the WiFi switch back into this mobility center as this switch is important for me to use daily ?

Many thanks and best regards to all , cheers - Jim :)