What in Windows 7 can affect page displays in ALL browsers?

I run IE (factory installed and current version updated), as well as the latest "portable" (portableapps.com) versions of Firefox, Chrome, and Opera. All FOUR of these browsers are experiencing the exact same problem with displaying certain webpages and I am trying to identify the source. When I try these pages on any other computer (even an old XP desktop) everything displays fine so I know the problem is my system. It is an Acer netbook running Windows 7 Starter (it's all I need for my "on-the-go" activities).

The basic display problem is on 2 websites: Gmail and Ymail. Using the "advanced" version of these websites, menus don't work and individual emails can take MINUTES to display. Using the Basic/Classic versions I had no problems and this was my workaround but now Ymail has eliminated that option and I find I have to work off a different computer for those emails.

I run several well respected antivirus (Avast, Clamwin) and antispyware (Spybot, MBAM) scans all the time, as well as a routine CCLEANER analysis and so far not so much as one blip of a malware item has shown up. I also tried fully uninstalling ALL of these just as a check and no change in the problem.

*** Somehow this "FEELS" like a java or javascript type issue but even though I eliminated every "JAVA" folder and file on the system I could find the problem persisted. Where else and what else in the system could be a possible culprit in this bizarre bug affecting 4 separate applications? ***

Everything else on every other software application in the system behaves perfectly and it is only this 1 display bug on these 2 competitor's websites that I am trying to isolate the root cause.

 

Win 7 64 bit Home Prem. on an Acer netbook here. No Java installed on the computer.
I use the Basic version of the <cough cough> new and improved version of Ymail. I have Javascript turned off at Yahoo. I get a message all the time that javascript is not running. I click continue and read my email with no problem.

Press the gear icon near the top right and if I remember one of the options is Basic.
It is limited but at least you get the page numbers back and you do not have to scroll through your entire inbox. You do not have to see the trending junl flashing at the top. I do not do Facebook so I have no interest in that cluttering my email page. I want a basic read, compose and send email.

Gmail: Press the gear
General, scroll down to Button labels. I've selected Text. If I select a message, I get more text displaying than I do with nothing selected.
Inbox, I've turned off all those tabs and only have Primary selected (default in the box above it)