FUSION.DLL: Assembly Manager For .Net Network!
Fusion.dll is a type of module called an assembly manager used in conjuncture with the Microsoft .net framework. Its purpose is to download and install functions of the .NET Microsoft framework. As it is a vital part of your main system, deleting it or trying to edit it is a bad idea unless you know what you are doing.
If you encounter any errors associated with the fusion.dll file, it could be the .net framework on your system is probably not functioning correctly.
Your first try at fixing this problem should be updating your .net framework via the Microsoft website. Sometimes this will fix the problem and give you the most current version of the program. However, if this will not work, mainly due to the fusion.dll being corrupted, your next option is to try and re-install the fusion.dll file itself.
There are a number of websites on the internet that offers different versions of fusion.dll files. http://www.dlldump.com/download-dll-files_new.php/dllfiles/F/fusion.dll/1.0.3705.60186/download.html might help.
If you can, stick with the Microsoft official website to avoid any security risks. Carefully refer to the error message to verify what the error is and follow the instructions on the website you choose. Monitor carefully the file as it may have a virus; use your anti-virus to check all of your files before installing them.
Remember, you can also contact http://support.microsoft.com/gp/wusupport if you have questions or are unable to solver the problem. They will usually message you back and provided you a link to instructions and a download to solve your problem.