Many legacy programs that your company relies on will run properly in Windows XP particularly when you set a compatibility box. The problem is, often these problems won't install properly, because their installer application doesn't support XP. However, since an installer is itself an application that can be put into a compatibility box there is a workaround.
Start off by opening the floppy disk or CD-ROM that contained the installation files, and right clicking on the Setup.exe, Install.exe, or other installation file. From the context menu, select the Properties command and then click on the Compatibility tab. Set the Compatibility to the operating system that was in effect at the time your first purchased the program, or failing that, set the compatibility to Windows 95. Then run the installation routine as you normally would. In many instances this approach will work.
You may find that in multi-disk installations that the installation will fail at the point where another disk is required. Or, that you can't set a compatibility box because the installation program is on a read-only medium. Therefore, create a new folder on your hard drive, or for your clients on a network share, and copy all of the installation files. Be sure that you've copied ALL of the files, including any that might be hidden or system files. Then try the installation again. If the installation fails, the installer may be looking for a particular path such as <PATH>/DISK 1/<FILENAME>. You may need to recreate this folder hierarchy to get your installation to work correctly.
Barrie Sosinsky is president of consulting company Sosinsky and Associates (Medfield MA). He has written extensively on a variety of computer topics. His company specializes in custom software (database and Web related), training and technical documentation.