For the old application to find a home on XP

For years, Windows 9x users have been reluctant to upgrade to Windows NT, but before and after the launch of Windows XP, Microsoft stopped supporting Windows 95. Industry insiders speculate that the next one to be abandoned by Microsoft is probably Windows NT 4.0 support. In fact, for users who still want to use older versions of the operating system, their choices are few.

There are two reasons people don't want to upgrade: huge hardware requirements and poor compatibility with applications that are not designed for Windows NT. Hardware is no longer a problem, and even the hardware of low-end systems is enough to run Windows XP. But what about software compatibility? Although on the surface, Windows XP is the least compatible version of Windows in the Windows family, it also includes some special tools that give users more choices than ever before. Some of these tools are explicit and some are implicit, allowing us to adjust the environment and make it more suitable for old applications.

Running DOS Programs

DOS programs are the oldest. Since Microsoft has removed the "DOS compatibility mode" from Windows XP, readers may think that it has given up support for DOS programs. In fact, the new option in windows xp makes running DOS programs much simpler.

Right-click on the DOS program and select Properties from the pop-up menu. Many of the tabs in the Properties dialog are similar, but the Compatibility tab is brand new. This tag allows us to set the program to run with 256 colors and 640x480 resolution. We can also disable the default visual theme that Windows XP imposes on the program.

There are also some less intuitive but more powerful tools. In DOS, we can carefully adjust the environment of the program by modifying the Config.sys and Autoexec.bat files. In some cases, we need to restart the system for a particular configuration of a program and then run other programs with the normal configuration. Windows XP allows us to define a specific Config.sys and Autoexec.bat for each DOS program.

Here's how to set it up. First, copy C:WindowsSystem32Config.nt and C:Windows System32Autoexec.nt to the directory where the DOS program is located, then edit them according to our needs and save them as a new file name. Pop up the Attributes dialog box for the DOS program, move to the Programs tab, and click the Advanced button.

Enter the Config and Autoexec file names created for this program, and Windows XP will run it in the custom environment of the program. This dialog also reduces the speed of DOS programs. Without this method, applications running well on systems with 50MHz chips may not run on systems with 850MHz chips.

Not a Windows program designed for XP

There are three reasons why older Windows programs can't run on Windows XP: they will query for a specific Windows version number, expectation Earlier versions of Windows API calls return results, and their desired user folders are in different locations or formats. These issues can be resolved by setting the Windows program to run in compatibility mode.

Right-click on the Windows program and select the "Properties" menu item. If you click on the "Compatibility" tab, a drop-down list will appear that allows us to set the operating system that best suits the program's operation. Click on the "Compatibility Mode" box and select the operating system. Using this mode activates a series of items that enable Windows XP to emulate an earlier version of Windows.

What should we do if we are not sure which version of Windows the program needs to use, or if the program has other compatibility issues? There is also a powerful tool hidden in the Windows XP CD that helps us carefully adjust the running of the program.

Application Compatibility Toolkit

In the SupportTools directory on the Windows XP CD, there is an Application Compatibility Tool (ACT). In April of this year, Microsoft introduced an upgraded version (version 2.5) that users can download from www.microsoft.com/windows/appexperience. The ACT includes four tools to improve program compatibility.

Application Verifier and PageHeap are two software developers. Software developers can use them together with the debugger to test the parts of Windows XP that may cause problems. But the other two software: QFixApp and Compatibility Administrator help to adjust the running environment of the program, so that the earlier application can run smoothly.

QFixApp enables us to make many low-level adjustments to specific applications. We won't discuss the 199 available adjustments in detail here. Below we'll discuss some specific adjustments that will make the program work smoothly.

Open QFixApp and select the program you want to adjust. Click on the "Layers" tab and select a layer. The layers in QFixApp correspond to the compatibility in the previous "Properties" dialog box of the program, select a layer, such as Win95, and then select "Adjust". We can see that the Win95 compatibility mode is a predefined 54 adjustments (Figure 1), but this number may vary depending on whether the latest adjustments are installed.