Replacement CDs or downloads of EZNEC v. 4.0 are no longer available. Please see "Upgrading to v. 6.0", below, for upgrade information.

I'm having trouble installing or running the program on a new computer.

See Using Older Versions.

My program was working, but now it fails with the message 'Runtime error 336:Component dwsbc36.ocx or one of its dependencies not correctly registered, a file is missing or invalid'.

Several spyware removal programs incorrectly identify dwspy36.dll, a file used by dwsbc36.ocx, as spyware and recommend its deletion. See "What is dwspy36.dll in theEZNEC program directory", below, for information about these files.) The message occurs when the file is deleted. As of v. 4.0.5, EZNEC no longer uses these files, so updating the program to v. 4.0.5 or later will solve the problem.

When I try to install EZNEC I get the message 'C:\WINDOWS\SYSTEM32\AUTOEXEC.NT. The system file is not suitable for running MS-DOS and Microsoft Windows applications' or other message involving AUTOEXEC.NT.

This is most often caused by the Windows XP Service Pack 2 (SP2) installation deleting (for unknown reasons) the Autoexec.nt file which is required to run 16 bit programs. The EZNEC installation program is intentionally an older type in order to keep download size smaller and updates simpler, and requires 16 bit(DOS-type) operation during part of the process. (EZNEC itself doesn't.) You should be able to solve the problem by locating a copy of Autoexec.nt in your C:\Windows\Repair directory (the directory might beC:\Winnt\Repair on systems upgraded from Windows 2000) and copying it into your Windows system directory C:\Windows\System32 (or C:\Winnt\System on some upgraded systems). If you need further assistance or this doesn't fix the problem, please let me know.

Will EZNEC 4.0 run under Windows XP? Vista? Windows 7?

Yes to all. EZNEC pro v. 4.0 users will need to download and install the latest update for Vista or Windows 7 operation, but no action is required for other users. For information about running EZNEC under 64 bit versions of these systems, see the next item.

Will EZNEC 4.0 run under 64 bit operating systems?

Yes. However, EZNEC v. 4.0.30 and earlier won't install on 64 bit systems, and installing the latest update won't correct the problem. If your original EZNEC v. 4.0 program is earlier than v. 4.0.30 and you've upgraded to a 64 bit operating system, a 64 bit compatible replacement might still be available -- contact me for more information. You can determine your version number by right-clicking EZW.exe or EZWpro.exe in Windows Explorer, choosing Properties, then clicking the Version tab. There is no problem running EZNEC v. 4.0 on a 64 bit computer, as long as the operating system is 32 bit. Except for versions specifically identified as 64 bit, Windows XP and Vista are 32 bit systems.

Will EZNEC 4.0 run under Windows 95?

I'm sorry, no. Following current trends, the compiler used for creating the calculating engines won't produce Windows 95-compatible code, and at least one of the third-party components used for advanced functionality won't operate under Windows 95.

EZNEC hangs whenever I try to open a top level menu, or at other times.

This problem occurs with EZNEC v. 4.0.16 and earlier on systems having a video adapter with an NVidia chip set,but it has been fixed in v. 4.0.17 and later programs. If you have this problem or have implemented the workaround of setting the program to run in 256 color mode, update your program by downloading and installing the latest update release.  EZNEC and EZNEC+ users should go to http://eznec.com/ez40updates/. EZNEC pro users should go to the URL printed on the distribution CD. If you're using the demo program, download and install the latest demo from http://eznec.com/demoinfo.htm. It will generally be necessary to start any non-pro program once after installing the update, then shutting it down, before it will run properly with an NVidia adapter without being in 256 color mode. Please let me know if you see this problem with any v. 4.0.17 or later EZNEC program.

Does EZNEC 4.0 use NEC-4 for calculations?

Of the five EZNEC v. 4.0 program types (demo, standard, EZNEC, EZNEC+, EZNEC-M, and EZNEC/4) only EZNEC/4 uses NEC-4. NEC-2 is the calculating engine used by the other EZNEC programs. See the next item, below, for more information.

Can EZNEC 4.0 use the antenna description files I created with an earlier version?

Absolutely! EZNEC 4.0 can even read and translate DOS EZNEC(.EZ) and ELNEC (.EN) files -- just include the extension (.EN) when specifying the name of an ELNEC file to open. Older versions of EZNEC can also read and use files written byEZNEC 4.0. EZNEC 4.0 uses the same plot file format as EZNEC v. 2.0 and 3.0, and can display plots saved by ELNEC or any version of EZNEC.

If I buy the CD-ROM version, does the CD-ROM have to be in place when running the program?

No. All necessary files are installed on your hard drive. The CD-ROM is needed only for installation. If desired, the CD-ROM files can be copied to a hard drive or Zip drive and the program installed or re-installed from there.

Where's the manual?

The manual is an integral part of the program. With EZNEC 4.0 running, In the EZNEC 4.0 Control Center(the main window), click Help on the menu bar, then choose Contents to view the manual. You can also open the manual to the relevant topic from many places in the program by pressing F1.

Is it possible to get a printed manual?

Yes, if you're willing to print it yourself. If you purchased EZNEC on a CD-ROM, you'll find it in the Printable Manual directory on the CD-ROM. Otherwise, you can download it. Clicking here will take you to the page where you can get more information. No pre-printed manual is available.

What are the EZNEC and EZNEC+ v. 4.0 segment limits?

The limit for EZNEC 4.0 is the same as for earlier versions, 500 segments maximum. This allows approximately 25 wavelengths of wire, or 50 beam elements. EZNEC+ 4.0 allows 1,500 segments, and the professional EZNEC 4.0 programs accommodate up to 20,000 segments.

Will EZNEC 4.0 overwrite previous versions?

EZNEC v. 4.0 will overwrite and update EZNEC v. 3.0 if installed in the same directory. It will not affect earlier (DOS) versions.

Will installing or uninstalling EZNEC erase or overwrite my existing description or trace files?

Absolutely not!

What's the difference between the upgrade version and full program?

There are no different"upgrade" and "full" or "new" versions. There's only one version, and it's a complete, independent program which doesn't require any other program or older version in order to install or function. The only difference between a new purchase and an upgrade purchase is the price; the program is the same.

Is there any difference between the download and CD-ROM products?

The installed program is exactly the same -- the only difference is in the format of the files used for installation. The download product is a single executable file, for convenient downloading. It expands and creates temporary files during the installation process, which are deleted when the installation is complete. The CD-ROM contains several files. Once installed, the programs and disk space requirements are identical. You may need to re-install EZNEC in the event of a hard drive failure or change to your computer system, so you should always keep either the CD-ROM or downloaded file. If you don't have any way to back up the downloaded file on some medium other than your primary hard drive, you should order the CD-ROM (with or without the download) to protect against loss of the program in the event of a hard drive failure.

My EZNEC v. 4.0 runs extremely slowly. Why?

Some versions of McAfee Antivirus software, when running in the background detection mode, can cause extremely slow operation of EZNEC v. 4.0 calculations. This problem can suddenly appear when the antivirus software is updated. Apparently, the antivirus software intercepts and analyzes the communications between the calculating engine and the main program. These communications are numerous and frequent, so the rather slow analysis process by the antivirus program greatly slows EZNEC operation. The only certain solution is to disable the background checking feature of the McAfee software while running EZNEC v. 4.0. So far, this has been reported only with McAfee version 4, and it appears that version 6 and later versions might not have this effect on EZNEC. This isn't certain, however. Other virus-detecting software could possibly have a similar effect, so if you encounter exceptionally slow operation, try disabling any anti-virus software you have running, and let me know if it solves the problem.

What is dwspy36.dll in the EZNEC program directory?

Some people have expressed concern about dwspy36.dll and wonder what its function is. This file is a "subclassing" control,part of a third-party utility package called SpyWorks, purchased from Desaware, a highly respected company which is well known to the VisualBasic programming community. This package allows functionality beyond that provided by Visual Basic or normal Windows programming but despite its rather sinister name is not "spy" software. When you attempt to reduce the size of graphical windows below a certain point, EZNEC limits the minimum size. This size limiting isn't possible with Visual Basic(except with "bounce-back" type operation), so a technique called"subclassing" is used. EZNEC intercepts the normal Windows message sent when a window is resized and directs it to code that limits the window size. The SpyWorks control (dwsbc36.ocx, which uses dwspy36.dll) allows this functionality. (It's apparently so named because of its ability to "spy on" -- intercept -- messages sent to and from the Windows operating system by applications during normal operation.) Some versions of EZNEC installed dwsbc36.ocx and dwspy36.dll in the EZNEC program directory; other versions installed them in the Windows system directory instead. An increasing number of spyware removal programs misidentify dwspy36.dll as spyware and delete it, which caused EZNEC to crash. Because of this problem, EZNEC was modified at version 4.0.5 to use a recompiled version of a similar DesaWare product, rather than dwsbc36.ocx and dwspy36.dll. V. 4.0.9 and later use an entirely different and newly compiled control. If you have any EZNEC program type of version 4.0.5 or later, you can safely delete dwsbc36.ocx and dwspy36.dll from the EZNEC program directory if they're there. I don't, however, recommend deleting them from the Windows system directory because some other legitimate application might be using them.
No version of EZNEC does keystroke logging or any other type of user activity recording, reporting, or Internet connection. For more information about the SpyWorks package, see http://www.desaware.com/SpyWorksL2.htm, and for more information about subclassing, see http://www.desaware.com/Subclassing.htm.

What language is EZNEC 4.0 written in?

The interface portion of the program was written in Microsoft Visual Basic 6.0. It consists of more than 50,000 lines of source code, not counting comments. I wrote every line, and it took about two years of essentially full time work to develop the first Windows version. The calculating engine is a modified version of the public domain NEC-2 program. It's written in Fortran, and incorporated as a separate executable file.

Where can I get more EZNEC models?

The CD included with the 20th and later editions of theARRL Antenna Book has several hundred EZNEC models of a wide variety of antennas. While specially created to work with the EZNEC ARRL program which also comes with the Antenna Book, they're also standard EZNEC files which work normally with EZNEC 4.0 and EZNEC+ 4.0. Even without the EZNEC files, the ARRL Antenna Book is a bargain, but the files make it even more so. Also, check http://www.cebik.com for models and other good information.

Upgrading to v. 6.0

All users who purchased an earlier version of EZNEC are entitled to a substantial discount from the full price when upgrading. To upgrade via the web, you'll need your Customer ID number which was sent by email or mail shortly after v. 6.0 introduction. If you want to upgrade and don't have your Customer ID number, email w7el@eznec.com to request it. Please don't purchase a new program at full price and request a refund.

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