A digital signature provides users with a way of identifying who published the software they are downloading from the Internet.
By distributing the Web runtime with a CAB file and digital signature, we ensure that most standard configurations of Microsoft Internet Explorer will accept the Web runtime application after the user responds "yes" to the Security Warning dialog when it is installed. Users who have set their browser security level to low will not see this dialog, since their browsers automatically accept digitally signed components.
Users with security levels set to high cannot run any ActiveX-based controls, regardless of the digital signature.
Because the CAB installation does depend on some Microsoft files, it contains an embedded link to the Microsoft Web site to ensure that it can obtain the proper files. If these files are needed, users are prompted to install the Microsoft files; doing so may impact the download and installation time of the control, due to the file size of some of these required files.