This seems like a storm in a teacup to me. An ISP is an ISP, it supplies data down a phone line, the o/s & browser at the other end is pretty irrelevant to me.
Having said that, running win 98 and god knows what browser - IE3, Netscape or some other superannuated piece of history probably puts you firmly in the hijacked end of the spectrum - I certainly wouldn't be keen to do my online banking on something that ancient.
So were it me, I'd be on for new machine - I seriously doubt a ten year old pc would be capable of running any contemporary o/s with any degree of fluency, then as for shifting data, bookmarks, email accounts etc across from one to another, it's simplicity itself - if I couldn't manage it, I would ask a passing 13 year old for help. This guff about arrogant BT & Yahell - presumably Yahoo is itself a form of ignorance and seems a bit too touchy to me - I'm just surprised a rant about premier league footballers wasn't tacked on the end. Buy a new pc & get on with it!