If you are having trouble installing Dreamweaver CS4, please check first that your computer and operating system meet the program's minimum requirements.
If your computer meets the requirements, and you still have problems, try the following:
If you have bought Dreamweaver CS4 as a standalone program or part of a suite, you are entitled to free installation support from Adobe.
Adobe does not offer installation support for the trial version. However, the only difference between the retail version and the trial is that the trial is time-limited to a maximum of 30 days. If your trial period expires prematurely, see this page for the likely reasons. You cannot reinstall the trial version on the same computer once it has expired.