How to get rid of extra plugins tab on Firefox 3.6 startup

Question

After a no-error crash Firefox 3.6 came back with extra tab. Tried every listed method could find but this tab could not be stopped from coming up when starting the program.
Help.
Don't want to upgrade!!! Everything was working fine until this. I changed nothing. Was working when all of a sudden it disappeared - no warning, no error message. When restarted instead of coming up with the usual list of tabs to restore, it came up in a new tab with a list of plug-ins it wanted me to update.
Would like to get back to where it was before crash. Some of the plug-ins can't be upgraded and were fine before this happened.
I do a lot of legacy work - all the way back to Windows 3.1, 4.0 along with DOS, and Mac OS 7, 8, & 9. I have two machines that are dedicated to hardware and software that are over 15 years old, whose output is in the same time, and at least the quality, of today's machines - These were high end machines in their day. Certain functions on any machine are limited by physics and mathematics, making these ol' clunkers comparable to today's in speed and quality. On a third is software whose functionality was never duplicated, whose producers are extinct as companies. Doing this kind of work has unearthed a dearth of folks who need legacy support, who don't want to (They are my customers. They are right! I can only question so much of what they want, very tactfully and carefully.), are not going to, or especially, can't afford to, upgrade, especially after hearing of costs and problems. I see a lot of early versions of Firefox, as well as other browsers, especially Netscape. I even keep one PC that runs DOS in order to work with folks who still use DOS based programs that work, especially POS stuff.
That's why I'm retro. I deal with fossils which include paleo-Firefox.

Answer 1

I just want what I had a few days ago back. Everything was working fine. I stay with the old version because it works for what I do. Foreign concept in today's world.
Our gripe is that we are having upgrades forced on us that don't increase our productivity and cause losses of time and money in the process. None of this is free. Time is money. Switching to Windows 7 has cost me more money than I could afford, for instance. Upgrading Firefox throws out the use of some plug ins - they don't work on the newer versions and can't be upgraded - function gone.
The Macs I still maintain are classic examples of upgrades not being useful forward steps for what I do. There are several programs were made for them that once their operating system upgraded became unusable, even in emulation. Their ease and functionality have never been reproduced in today's software. The old browser works fine on them today. I don't need the new features. I use VMWare in Windows 7 to run a program that, according to the maker, upgrades for the "insignificant" price of $999. That ain't chicken feed! It's the only way it will run. There was no problem with this on XP.
In addition, I use these old machines in order to work with customer's old systems. When there are problems, a lot of what they have won't run on the newer machines at all. We get stuff so old we have to build machines to run it on as needed. And yes, a nightmare in extinct data, file formats - fun, fun fun.
Yes, we are helping folks stay in the stone ages of computing. We can do no more than advise them on what is available and how it works. The final comedown is theirs since they are the people paying the money. On my machines I am the final say and I too keep legacy equipment both for working with customer problems and as I said, I have old software as well as hardware that does not work on today's OS and still works fine and is too costly and troublesome to upgrade as well as offering no improvement in quality and speed of output.
Theory behind us now, how about some answers for the original question. Only in an ideal world is upgrading smooth. We don't live in one, nor would most of us want to. We are individuals.