As with any exam, it will vary from person to person as to what is deemed to be difficult. Some of the topics you may have trouble with are Cascading Style Sheets (CSS), Microsoft Installer (MSI) Deployment and Extensible Markup Language (XML).
Cascading Style Sheets
Web pages can be thought of as having three layers; content, presentation and behavior. The content layer has the information in it that the designer wishes to present. The presentation layer contains the look and feel of the web page. Cascading Style Sheets is the way to control the presentation layer of the web page. The benefit of using CSS over regular HTML is that the styling can be kept separate from the information in the content layer. It also saves in bandwidth and allows an easy way to provide a consistent experience for the user.
Microsoft Installer (MSI)
Microsoft Installer is the method preferred by Microsoft for installing, maintaining, and removing software on Windows systems. Using MSIs for installation allows the Windows system to keep track of all software installed and to provide features such as rollback and versioning. Creating an MSI can be accomplished using several different software packages such as Install Shield, Visual Studio, Wise Installer, etc. As a developer, you have options on how a program will be installed, such as silent or unattended.
Extensible Markup Language
It is important to understand that XML is not a replacement for HTML. In most web applications, XML is used to transport data, while HTML is used to format and display the data. XML specifies neither semantics nor a tag set. In fact, XML is really a meta-language for describing markup languages. This means that XML provides a facility to define tags and the structural relationships between them. Since there is no predefined tag set, there aren’t any preconceived semantics. XML is the most common tool for data transmissions between all sorts of applications.