This week's PST (Personal Security Tip) helps Windows (NT/95/98) users determine, instantly, whether their cable, DSL, dial-up or ANY other connection to the network allows outsiders to connect to their machines. It also shows, step-by-step, how to block such connections.

Use this PST any way you feel it could contribute to information security. Once you have checked the material and feel comfortable with it, you may forward it to other users, print it and hand it out, post it, send it to news groups or send it to the local newspaper and encourage them to print it.

News stories about cable modems and DSL lines allowing people to get into your computers and read your files are too true. If your personal computer is running any version of Windows, it's very possible that your machine is vulnerable even when it is connected over a regular dial-up line or a corporate network. (One exception is AOL which blocks the vulnerability on behalf of its subscribers.)

A new, free service has just been posted that will help you find such vulnerabilities and correct them.

It was developed by Steve Gibson, one of the industry's pioneering programmers. He is the developer of many useful PC utilities, including SpinRite. To read about the free service, to test your system, and/or to see how to fix the vulnerability, point your browser to:

If you have a suggestion for a future Personal Security Tip, please send it to me.