If you're dealing with a text that's got the same error running all the way through it then it's incredibly tedious to go through it and remove the errors one by one.
TextSoap is a very powerful but simple text scanning and searching tool which allows you to search and scan texts from a variety of sources looking for words or phrases that have been written in error. This Windows version is actually a more basic "Classic" version of TextSoap for Mac but follows pretty much the same functionality and has most of the same features.
TextSoap works either via it's own built-in editor or a plug-in inside an application. It's not just a text replacement tool however - it can also help with formatting issues such as erroneous bold and italic tags as well as HTML tags. To select what type of detail you want to cleanup, just go to All in the menu bar and all the possible options will be displayed.
Beyond this, TextSoap will also remove extra spaces, fix broken paragraphs and remove email forwarding marks. Although it's job is rather simple, working out how to use it isn't quite so easy. Although there are loads of preset clean-up features available, TextSoap usually ends up selecting absolutely everything including those parts of text that you don't want to change.
That said, TextSoap is still much more efficient at finding and replacing errors than going through them yourself.