Wireless connection problem whenever I switch on my...

you need to isolate first which of the devices is giving you the problem.
- check first the connection from your modem by connecting a computer directly to it. check if you'll loose the connection from the modem. if so, you need to check with your internet provider if they're having maintenance from time to time since that could be the reason why the router is not providing the connection to your laptop automatically and you need to restart it to sync with the modem first.
- if you have a proper/stable connection directly from the modem, next thing to check is the connection from the router. check if your wired computers are getting the same problem. if so, you may need to check for loose/faulty cables or you may need to upgrade the firmware of your router. if the wired computers are not getting the same problem, it's time to check the wireless settings of the router.
* access the router's page by typing http://192.168.0.1 on your web browser's address bar (default username is "admin" while the default password is "password")
* go to the wireless settings page and check if the wireless name (ssid) is not the default. if it's still using the default ssid, customized it to prevent interference from other dlink network near your area
- if you have check the modem and the router, it's now time to check the wireless adapter, make sure that it is connected to your own network. if you are using it's software utility, make sure that you have created a profile using the same ssid as of your router. you can also update the driver of your wireless card if you have checked the above mentioned and you're still having the same problem
you can also try to use another wireless computer and check if it'll experience the same problem to properly isolate the if it's the router or the wireless adapter problem. you can also try to install the wireless card to another computer and check if you'll have a stable conection. if so, there could be a software (like a firewall or an antivirus software) that is giving you the problem.

hope this'll help you and just ask me if you have other concern.

ciao!