This is usually for me a process of getting to the bottom of what is actually causing the freeze. It's not usually the browser, expecially with Chrome, unless it's an extension. Chrome is really well written. To test extensions, disable your browser extensions and see if the problem is corrected. If not, next time you sense the freeze happening, open Task Manager and click on the CPU column header so you can see what's using most of the processor. It will almost always have something to do with that process.
If it's svchost.exe or another Windows process, look at how much memory it's using and make a mental note. High RAM usage for Windows processes can mean you have a hung update or something could be "borrowing" svchost.exe or something else Windows. Example in W7 would have been sidebar.exe. Some widgets could appear to be svchost.exe, but the widget was the problem. Has to do with programs that run as a service or have an associated service installed on the PC.
Post back what is using the processor. That would help. Zemana scan will probably find some things if a MBAM scan did too.