Adding, Removing, and Managing Programs in Windows 7
- Dealing with User Account Control
- Dealing with Compatibility Issues
- Running Legacy Applications in Windows XP Mode
- Installing Programs on 64-Bit Editions of Windows
- Managing Startup Programs
- Managing Running Programs and Processes with Windows Task Manager
- Running a Program as an Administrator or Another User
- Uninstalling Programs
- Setting Default Programs, File Type Associations, and AutoPlay Options
Dealing with User Account Control 158
Dealing with Compatibility Issues 160
Running Legacy Applications in Windows XP Mode 164
Installing Programs on 64-Bit Editions of Windows 170
Managing Startup Programs 172
Managing Running Programs and Processes with Windows Task Manager 176
Running a Program as an Administrator or Another User 178
Uninstalling Programs 179
Setting Default Programs, File Type Associations, and AutoPlay Options 180
You don’t need a wizard or a Control Panel applet to install an application in Windows 7. Setting up a new program from a CD or DVD is typically a straightforward matter of inserting a disc and following the instructions that appear courtesy of your AutoRun settings. Setting up a program that you download is usually a matter of clicking Run or Open after the download has finished. In neither scenario do you need a wizard to hold your hand.
That’s the theory, at any rate. In practice, there might be hurdles to surmount or hoops to jump through when it comes to installing programs. Potential complications come in two flavors:
User Account Control (UAC)
The first of these is usually no more than a minor annoyance. The second can be vexatious, but it usually arises only with programs designed for an earlier generation of operating system.
In this chapter, we’ll survey the hoops and hurdles and everything else having to do with the addition, removal, updating, and management of applications in Windows 7. We’ll also look at Windows XP Mode, a free download for Windows 7 (Professional, Enterprise, and Ultimate) that can let you run legacy applications that can’t run directly in Windows 7.
Dealing with User Account Control
Rare exceptions aside, the rule in Windows 7 is this: To install a program, you need administrative credentials. Software installers—the programs that install programs—typically create files in system folders (subfolders of %ProgramFiles%) and keys in protected registry locations, and these are actions that require elevated privileges.
Installing the program files and registry keys in protected locations protects your programs (hence, you) from tampering by malicious parties, but unless you have disabled User Account Control altogether, you need to deal with UAC prompts to complete the process. If you install a program while running under an administrative account, a UAC prompt will request your consent for the actions the installer is about to undertake. If you install while running under a standard account, you will be asked to supply the name and password of an administrative user.
Windows 7 employs installer-detection technology to determine when you have launched an installation process. This technology enables the operating system to request credentials at the time the process is launched, rather than waiting until the installer actually attempts to write to a protected location.
The system presumes that any process with a file name containing particular keywords (such as install, setup, or update) or any process whose data includes particular keywords or byte sequences is going to need elevated privileges to complete its work, so the UAC prompt appears as soon as the installer process begins. After you have satisfied the UAC mechanism, the process runs in the security context of TrustedInstaller, a system—generated account that has access to the appropriate secure locations.
The same technology that detects an installation process also recognizes when you’re about to update or remove a program. So you can expect to see UAC prompts for these activities as well.