Right, I'd better start at the beginning or I'll look like an even bigger numpty than I actually was.
Sometimes my mouse has spasms where the cursor flies all over the screen and clicks itself at random. When it does this I usually let it sort itself out as it will be over in a few seconds. There is not usually any harm done, except today I noticed it had created a narrow strip down the side of my mIRC window that I could not figure out how to remove. In my increasingly frustrated efforts to remove said strip, I also accidently removed my toolbar that has things such as "File" and "View" on it.
If anyone can give me instructions on how to put everything back how it was, this would be most helpful as I do not want to have to reinstall everything over again.
Here is a screenshot of my mIRC window at the moment (the garish colour scheme is intentional):