UAC and Installers

Windows 7 uses 'installer-detection' technology to detect when an installation process starts, allow UAC to request permission required to install software before the installation process starts writing data. If granted, the installation process will run under the context of the TrustedInstaller account. Installer detection consists of a database of keywords or byte sequences typical of installation programs. If UAC fails to detect the installer, the installation may fail because the installation process may not have the required priviledges to write files or registry keys to protected system areas. If this happens, right-click the installer program and choose 'Run as Administrator'. Installation processes that require a reboot during the installation process, may require that you logon with an administrator account for the installation process to continue.

Compatability Options

When installing legacy software, it is a good idea to manually set a restore point, as older installer routines may not be able to do this automatically

Installing software designed for early versions of Windows may cause Windows 7 to launch the Program Compatibility Wizard, which will unhelpfully provide a link to the manufacturers website, for you to download a more recent version of the program. If you continue with the install, or even if you cancel, the Program Compatibility Wizard will pop-up an alert that the program may not have installed correctly. The dialogue allows you to assert that the program installed satisfactorily or select to reinstall with compatibility settings automatically selected by the wizard.

The compatibility options for an installed program can be adjusted by selecting the Compatibility tab from the application launchers 'Properties' dialogue. The 'Run in Compatibility Mode' option allows you to also select the appropriate Windows version to for compatibility mode to emaulate, adjust display settings, and set the program to run with administrator priviledges.

Windows XP Mode

Windows XP Mode is available to run legacy programs that require a Windows XP environment to run, for example Internet Explorer 6, or that simply cannot be installed in tandem with existing Windows 7 software.

Windows XP Mode is only available for Professional, Enterprise and Ultimate editions of Windows 7, and consists for a licensed virtual hard drive image of Windows XP SP3 32-bit that can be run under Windows Virtual PC or other virtualisation software. Windows XP Mode will run on machines even if the processor does not support hardware virtualisation. Programs subsequently installed in the XP virtual image, will appear on the Windows 7 start menu in the 'Windows XP Mode Applications' menu. When launched from the windows 7 start menu, the virtual environment is initialised but the application runs as a window on the windows 7 desktop. Although XP Mode applications can run as windows on the Windows 7 desktop, drag and drop is not enabled between the two environments - however regular cut and paste operations are supported

x64 Software

16-bit applications will not install on 64-bit versions of Windows 7. Some 32-bit programs will also not run on 64-bit Windows 7. Both 32-bit and 64-bit versions of Internet Explorer are installed on 64-bit Windows, and the 32-bit version runs by default, to ensure support for plugins only available in 32-bit formats. 32-bit programs are displayed in taskmanager with a '*32' next to the image name

Startup Programs

There are a myriad of locations available to make a program run at startup:

• The Startup folders in the current user or 'all users' profile
• The Run keys in HKLM and HKCU (Software\Microsoft\Windows NT\CurrentVersion\Windows)
• RunOnce and RunOnceEx keys in the registry
• RunServices and RunServicesOnce keys in the registry
• UserInit and Shell subkeys for Winlogon under HKLM in the registry
• The 'Load' value of HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows
• Scheduled Tasks
• Load= and Run= values in the [Windows] section of %SystemRoot%\Win.ini
• Group Policy creating entries in HKLM and HKCU at Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run
• The BootExecute value of HKLM\System\CurrentControlSet\Control\Session Manager
• DLLs loaded by windows to add capabilities to the Windows Shell
• Logon scripts

Use msconfig to troubleshoot startup programs, also available from Programs > Administrative Tools > System Configuration

Default Programs

The 'Default Programs' item on the Start Menu allows you to set a program as the default application to handle particular file types or protocols, or you can associate particular file types by extension with a particular application. Using the 'Set Default Programs' option, you can either associate all file types and protocols that an applicaton can handle to that application, or you can select individual items to associate with the application.

The choice of Default Programs does not cover all files types and protocols. For a more complete list, you can use the File Types Association dialogue instead, which allows you to associate any registered file type or protocol with a preferred application. If a particular file type is not in the list, you can right-click a file of that type and associate it with a program from the General tab of the properties page. The 'Opens With' label shows the currently associated application: use the 'Change' button to change the association. You can also provide a descriptive name for the file type in the ensuing dialogue. If you inadvertently associate a program with an inappropriate file type, the program will remain in the recommended programs list for the file type. To association can only be removed by editting the registry key at 'HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\filetype\OpensWithList.

The 'Default Programs' menu also contains links for changing autoplay options and set default programs for all users of the computer. Autoplay options include 'Always Ask Me' and 'Do Nothing'.

Change a File Types Name

Sometimes although suitable file associations exist for a file type, there is no registered description for the file type. For instance, a perl script might be runnable by double-clicking it, if you have installed perl, but the file type is listed as 'PL File' by default. To correct this, search HCR for the '.pl' key. The (Default) value for this key will be set to 'Perl'. Now search HCR for the 'Perl' key. Change the value for the (Default) key to 'Perl Script'. After a reboot, your perlscipts will display as type 'Perl Script' instead of 'PL File'.