my laptop will come to a "pause" all of a sudden for approximately 30 seconds. Although the symptom is intermittent, but within this 30 seconds or so, the system doesn't respond to wherever cursor clicks nor to any key. I wasn't able to see if there is any error being logged in the event viewer or any system service running in the backgrounds that might cause this "pause". Could anyone please give me some quick advise for this issue? much appreciated.

If you press the CTRL-ALT-DEL key while your computer seems frozen, does that bring up your Task Manager right away? If so, look to see what programs are running. Does this happen only if you are NOT on the internet? Some spyware programs may be looking for an internet connection to send their reports back, and causing your computer to stall while it looks for a connection. Is your HD light flashing while it is paused? Could be your system is swapping out files to the temp folder. Try to see if the computer freezes in Safe Mode. Safe Mode will not load many drivers, so you color will be off, no internet or network connections etc., but if it doesn't freeze, you will have more info as to whether it is something loaded when booted in normal mode or not.

I used to have this problem on an old Toshiba laptop. It seemed to have something to do with Microsoft Findfast; after I got rid of findfast, the problem went away. See if you have findfast running and if so, get rid of it. See if that solves the problem.