When I had an internet connection problem a couple years ago it was due to my wireless phone causing interference with my wifi signal. I had to wind up getting a wireless phone that was on a different frequency and the problem was gone.
Another common fix for wifi internet connection problems is the firmware needing an update/fix as Hostlumina stated.
Are you from the Philippines?!?! If yes, then you need a lot of luck. Not that i know of any tools that could really stabilize internet connections from other countries but if you're from here, then you just have to try what works for you best. It would be trial and error because different ISPs works best in different places so you really have to try it for yourself. The problem here is that they implement the "lock-in" period. If you want to test their internet connection, you'll be locked for their terms for 1 year. And if you're not satisfied and wanted to get out, you'll have to pay the internet connection for the remaining month that you are locked in. So best ask what is the best ISPs at your place. You could ask computer shop owners for their feedback.