Many medical practitioners look at the legal requirements "imposed" by Congress as a necessary evil, failing to see the fact that it is really just a way to help them protect their patients' private information, keep their staff accountable and stay in business in case of an emergency or natural disaster.
New OS and Application vulnerabilities are discovered
almost every day.
Also, the default Windows installation is configured for usability, and not for security. Even if
Windows Vista changed that, incorporating many new security features "out of the box ",
Vista makes the use of legacy applications more difficult, slowing down it's adoption
and it is so easy to go overboard and just disable the “annoying” security features.
Many unnecessary services and applications are loaded by computer manufacturers,
aimed to the household use of the computer, making it not only slower
but also unsafe for medical providers.

