Problems after windows 8.1

Dear all Greetings

I am facing problem with my 

Dell Vostro 3550, i5-2450M(2.50 GHz-Turbo Boost3.10 GHz) , RAM - 4 GB , Graphic - ATI Mobility Radeon HD 6630m 1GB(Switchable Graphics) , Chipset Intel PCH HM67, Win 8.1 Pro x64

From the time I upgraded from windows 8 to 8.1 Its facing problem,I do even check for windows official update.

1.Wifi does not get connected at first time,after twice or thrice it gets connected.

2.It Heats alot(already installed graphic driver from ATI)

3.When I start it some time it give me 5 beeps(CMOS battery failure may be)-but don't know where to buy.

These are main problems

thnx in advance for help.