Having computer performance problems and especially a ajaxcontroltoolkit dll could not load file or assembly error can be quite frustrating. Many times it comes from nowhere, without doing anything special on your computer, and right after that you try to understand what happened and how it can be solved. Follow this quick report - by the end of it you'll be able to repair this problem by yourself.
Before we discuss how to solve these problems, remember one thing - with today's high-end windows technology there isn't a problem that can't be solved. If you don't know what dlls are, here is a quick review. Dll (dynamic-link library) files are part of any application; they include info which is necessary for any of your installed applications to be able to run. Dll problems usually take place after installing a new version of software over an 'older' version, and also after uninstalling programs. Once there is a small problem during installation/reinstallation/un-install, then this is a good reason why you start experiencing these unexplained and irritating problems.
Luckily, many of these problems are 'fixable' even if you are not an expert - you can easily 'clean' a ajaxcontroltoolkit dll could not load file or assembly error by installing a professional and easy to use Windows registry cleaning software. These types of programs specialize on scanning your Personal computer and fixing various known and unknown system problems including 'corrupted' DLLs. The most effective way to try and 'clean' these annoying errors can be done by examining your windows system with one of these programs - you'll quickly find out that most of them offer free pc scans.
Quick advice before wasting days and nights on web searches, or hiring someone to remove this ajaxcontroltoolkit dll could not load file or assembly error, I would advise you to download one of these registry repairing applications and let it easily scan all your dlls, identify and remove your pc's dlls & other problem(s) (there might be few hundreds and even thousands of dlls in an average pc). Try it right now - a wide range of of these tools not only offer free system scan, but free of charge fixes (limited for specific problems), so you might be able to 'clean' this problem in just a few minutes from now.