Hi samkidg
. . . And Welcome to the Tech Support Forums.
I would expect that your earlier calls resulted in advice to run extra malware scans -- if you haven't checked that angle yet, give it a go. If you find evidence of a serious infection, try a look at our TSF Security forums 5-Step Security Checklist ---
IMPORTANT - Read This Before Posting For Malware Removal Help --- You definitely want to try to get your system as clean as possible.
I also would expect that they had you check your IE settings. You could try to set things to defaults & see if that changes your luck. You could also try using Add/Remove Programs in Control Panel to revert IE to the previous version, and then download & install the latest version compatible with your version of Windows (probably IE 5.5 or thereabouts).
Another tactic might be to install Firefox & see if it connects OK to the secure sites (if your PC isn't malware-infected, it should connect OK).
Let us know if these don't help, as there are other things you can try as well.
Best of luck!
. . . Gary