Computer Information & Shopping

Shared Library Files
Many software firms use DLL (Dynamic Linked Libraries) in developing programs. They are kind of like a tool box from which the programmer chooses the one needed. Even though the program being created may need only a couple of "tools" from this DLL, using them saves programming time, which is expensive. This is a safe and efficient procedure, for the code in the library is well tested and will run reliably.

Other software developers use the same library. Some DLLs are used in many programs. For you, this means less disk space required on your system, for only one copy of the library is needed.

You also benefit in that you pay less for the software and it runs reliably. It's hard to see anything negative in such a procedure. Or in software using any other shared procedures. For example, you might have several programs that use a common routine that is part of connecting your system to the Web over a phone line.

All About Versions
Most companies developing software will use the latest version of a DLL. It contains changes and enhancements over earlier ones. Thus differences exist between them.

This is true of different versions of other software. The latest version of IE (Internet Explorer), for example, contains changes and enhancements over the previous one. Migrating from the current version to the latest, can mean installing what amounts to almost a new program.

The Catch In Upgrading Or Installing Software
When you install an upgrade or a new piece of software, any DLLs used will also be installed. Windows makes the rules in this. An older version of a DLL is not allowed to overwrite a later one. But a newer one IS allowed to overwrite an older one. Here's how things can go wrong.

Suppose you have a program call SPLAT, another called SPRANG, and a third call SPUNK. Suppose they all use a DLL called STUFF. If you upgrade SPUNK, and the upgrade includes a new version of STUFF, then quite suddenly SPLAT and SPRANG may not run properly. That is, they are now forced to use a version of STUFF the programmer had not planed for.

While it's quite likely a new DLL will run just fine with older programs, it may not. If your older programs won't run well enough to suit your needs, you may be forced to upgrade to later versions. Unfortunately, this may not solve the problem if the older DLL is still in use.

What This Means To You
If you are a casual user of your computer, and load up something new about once a month, the chances are you will never face the problem described above. The worst that is likely to happen is that as new software is added, older programs do not run in quite the same way.

If you are a serious computer user, and depend upon one as an integral part of your business, take the position you won't upgrade or install new software unless you are absolutely forced to do so.

If you need a program, by all means install it and go. But be hesitant in playing the game, "I think I'll try this." Why risk it?

Bob McElwain - Want to build a winning site? Improve one you already have? Fix one that's busted? Get ANSWERS. Subscribe to "STAT News" now! mailto:join-stat@lyris.dundee.net Web marketing and consulting since 1993. Site: Phone: 209-742-6349