It seems like I fixed it with solution provided in another similar thread. I changed channel to 6 and channel width to 20mhz. Haven't had this problem for last 2 days. Thanks anyway.

Model : Hardware Version : Not Clear Firmware Version : ISP : Hi! I have a TL-WR740N router and Acer Aspire 5750G laptop. The problem is that once in a while the laptop loses internet connection and...