My PC is very slow and it takes long time for surfing

Hi guys,
I have Acer Iron Gray 11.6" C710-2856 Chromebook with Windows 7 installed in it.
I have not installed many programs on my laptop. But, it is very slow while bootup and also while browsing. I have AVG plus Spybot and also the CC Cleaner and I am using it daily. Sometimes I use malware bytes software to identify and delete any malware. Even after taking all precautions my system is very slow. I am not understanding what is the reason.
Can somebody help me on how to Make it speed? Please advise. Thanks a lot in advance!
