It seems that you can't perform a silent install on EXE files. This can only be done to MSI ones. However, you can use a program to convert the EXE file to a MSI one. There are plenty of solutions for this problem on the Software Informer's database. After you created the MSI file, open the Command Prompt from Start > Accessories > Command Prompt. Use the CD command to navigate to the folder in which you have the MSI file, and type the following command : msiexec /package Update.msi /quiet. ( Be aware that Update.msi is the file that you recently converted and the name could be different. Input your own file name).
