Web pages won't load

[breadcrumb]

I was not sure what topic to put this question under, but anyway, for the past week my desk top computer has been not working because even though I am able to connect to the internet, no web pages will load. And even a Bible library I have installed on my pc will come up but then won't respond and it has nothing to do with internet connection! I have a Dell optiplex 780 with Windows 7 on it. The guy that has fixed my pc before doesn't answer my messages (I do pay him for his work!), so I don't know what to do. I can't afford to call a regular tech. I only have $100 in the pc as I bought it about a year ago on ebay as a refurbished one. I'm almost wondering if I should just buy another refurbished pc, since it might be so expensive to get it fixed. I just don't know! Please advise! I am very ignorant about all things technical.
Thank you.

[DaveLembke]

First things first I would install an antivirus and malwarebytes to it and scan it to make sure that the browser hasn't been hit with anything that is causing DNS redirects etc. Nothing should be connecting through a proxy etc as well.

If it comes up clean then use another computer to download and save the firefox installation to a USB stick. Then connect USB stick to this computer and install Firefox. Then see if the internet works again. If it works again then IE is messed up. If it doesn't work, look at your DNS and Gateway setting to make sure you have outbound traffic to internet. Try to ping www.google.com from command shell and see if google replies back with successful pings as well. Google for me shows 30ms latency and pings with no problems. Latency will vary but knowing how much latency you have would help as for if it shows lost pings and then latency of 4000ms then there is something very wrong with the network to this system.

[breadcrumb]

Dave, I thank you for all the info, but it is over my head. I am actually on the computer that wouldn't load pages right now! I don't know why it works occasionally but not most of the time! Anyhow, I have a firend who may be available in a couple of weeks to  work on this pc. He is very tied up now, so when he's got some free time, he can read your advice and use it. Thanks again!
bc