Connected, but no internet

Hi all,

I have a problem with my internet: sometimes (happens every day or two) my computer shows that I have a strong connection to the internet but when I open Google Chrome, the browser takes a very long time on a white screen loading the page, and after about a minute it shows a page showing the message "Unable to access the network." Running the troubleshooter gives no problems or solutions, and after running any other application such as Steam, the application does not necessarily show that I do not have connection, but it doesn't run properly and won't load anything that requires an internet connection. The problem is not in my router, because I am able to use internet on several other devices. I tried flushing my DNS and restarting my computer, both with no luck. Furthermore, a particularly weird problem is that when I try to open control panel, it takes forever for the loading bar (green at the top) to fill, then it ends up not loading at all (just a white page). Is the control panel connected with the internet? All other application load fine (if not using internet). Keep in mind this only happens ocassionally, but lasts for at least an hour.

I have only gotten this problem after I recently installed a program called System Mechanic Pro (iolo) from humblebundle.com, and ran a system checkup and continued to use its services which include "optimizing the internet," deleting random files, and doing something with the registry. I ended up deleting it because I thought it would mess up my computer more. I'm not really experienced with this stuff, but could the problem be that System Mechanic Pro deleted some critical files or tampered with the registry? I can redownload it to provide more information if nevessary. Or is this a virus? I have seen somewhere online that people restore their registry to default... what does this do? What is the importance of
the registry? Sorry for all these questions.