Windows 7 is everything the advertising says it is; innovative, intuitive, and user friendly. It puts the user in the driver's seat making it easy to use the computer as a tool.
But a couple of weeks ago my Windows 7 lost the ability to install any program that did not come with its own installer program; which was just about everything. I spent hours researching the condition and so I am passing this research on to help others who will surely have the same problem.
The condition's main symptom is that instead of installing a program it crashes with an error message "Windows Installer Service could not be accessed." Programs do not load.
If your Windows 7 shipped with an actual operating system disc, you are in luck. The repair program on that disc should fix your program.
If you bought your machine from one of the box retailers (like Best Buy), your computer probably came with a recovery partition and therefore, did not come with the special repair program. You are out of luck. You can try the options on the Microsoft tech site listed here. But, as the last option states, you'll probably end up wiping your harddrive; reloading Windows 7 and all your data, files, and preferences.
The issue is with the Windows Installer Program Version 5. Although Windows Installer is available for download over the internet in other versions it has not been made available yet in version 5, even though computers have shipped with version 5 since 2009. I only know this because that is how long this problem has existed.
If you already own a Windows 7 machine try to obtain a complete version of the operating system by asking the manufacturer for an actual disc. If you are told about the partition tell the manufacturer that files to fix a Windows Installer problem are not on the partition; only the actual operating system disc will do. Do this before you have a problem.
If you are considering a Windows 7 machine, make sure the computer comes with the actually operating system discs. If the box store won't provide the discs consider a local computer store that builds computers to specifications. These type of businesses generally provide better service if you experience problems (at least your machine and all your confidential data won't be sent to someone and some place you don't know.)