PC browser issue

I could really use some tech support on a used Dell PC I currently picked up for SDR use.



PC is a Dell desktop computer, 2.0GB RAM, Intel Celeron 2.19GHz CPU, currently running Windows 7 Home Premium, 64 bit. IE is my web browser. Only antivirus is Microsoft Security Essential. Windows 7 is set to update automatically so I believe all my programs are up to date.



Problem #1...

IE is my current browser and when I try to go to certain websites such as Yahoo, Google or my gmail, all I get is a blank page. Any other site loads fine. I need to access my gmail in order to gain access to the Kaspersky antivirus download.



Problem #2...

I would like also change my web browser to Mozilla, but when I hit the "download" button on the Mozilla page, nothing happens. I check my download folder and it is not there.



Problem #3...

I have tried to download a driver for the printer I am trying to use, but I can not seem to download it either. The printer is a Dell Photo AIO 922.



I have turned off my Windows firewall and tried to access the above sites with no luck, so I turned my firewall back on. Bing seems to be the only search engine I can access. I even uninstalled the Bing Bar thinking that would help but not luck. Is it possible all these issues are related?