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

See Using Older Versions.

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

Several spyware removal programsincorrectly identify dwspy36.dll, a file used by dwsbc36.ocx, asspyware and recommend its deletion. See "What is dwspy36.dll in theEZNECprogram directory", below, for information about these files.) The messageoccurs when the file isdeleted. As of v. 4.0.5, EZNECno longeruses these files, so updating the program to v. 4.0.5 or later willsolve the problem.

When I try to installEZNEC I get the message 'C:\WINDOWS\SYSTEM32\AUTOEXEC.NT. The systemfile is not suitable for running MS-DOS and Microsoft Windowsapplications' or other message involving AUTOEXEC.NT.

This is most often caused by the Windows XPServicePack 2 (SP2) installation deleting (for unknown reasons) theAutoexec.nt file which is required to run 16 bit programs. The EZNECinstallation program is intentionally an older type in order to keepdownload size smaller and updates simpler, and requires 16 bit(DOS-type) operation during part of the process. (EZNECitselfdoesn't.) You should be able to solve the problem by locating a copy ofAutoexec.nt in your C:\Windows\Repair directory (the directory might beC:\Winnt\Repair on systems upgraded from Windows 2000) and copying itinto your Windows system directory C:\Windows\System32 (orC:\Winnt\System on some upgraded systems). If you need furtherassistance orthis doesn't fix the problem, please let meknow.

Will EZNEC 4.0 rununder Windows XP? Vista? Windows 7?

Yesto all. EZNECpro v. 4.0users will need to download and install the latest update for Vistaor Windows 7 operation, but no action is required for other users. For informationabout running EZNEC under 64 bit versions of these systems, see thenext item.

Will EZNEC 4.0 rununder 64 bit operating systems?

Yes.However, EZNECv. 4.0.30and earlier won't install on 64 bit systems, and installing the latestupdate won't correct the problem. If your original EZNEC v. 4.0program is earlier than v. 4.0.30 and you've upgraded to a 64 bitoperating system, contactmeforinstructions for obtaining a new installer. You can determine yourversion number by right-clicking EZW.exe or EZWpro.exe in WindowsExplorer, choosing Properties, then clicking the Version tab.There is no problem running EZNEC v. 4.0ona 64 bit computer, as long as the operating system is 32 bit. Except forversions specificallyidentified as 64 bit, Windows XP and Vista are 32 bit systems.

Will EZNEC 4.0 rununder Windows 95?

I'm sorry, no. Followingcurrent trends, the compiler used for creating the calculating engineswon't produce Windows 95-compatible code, and at least one of thethird-party components used for advanced functionality won't operateunder Windows 95.

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

This problem occurs with EZNECv. 4.0.16and 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 youhave this problem or have implemented the workaround of setting theprogram to run in 256 color mode, update your program by downloadingand installing the latest update release.  EZNECand EZNEC+users should go to http://eznec.com/ez40updates/.EZNECprousers should go to the URL printed on the distribution CD. If you'reusing the demo program, download and install the latest demo from http://eznec.com/demoinfo.htm.It willgenerally be necessary to start any non-pro program once afterinstalling the update, then shutting it down, before it will runproperly with an NVidia adapter without being in 256 color mode. Pleaselet me know ifyou see this problemwith any v. 4.0.17 or later EZNECprogram.

Does EZNEC 4.0 use NEC-4 for calculations?

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

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

Absolutely!EZNEC 4.0can even read and translate DOS EZNEC(.EZ) andELNEC (.EN) files -- just include theextension (.EN) when specifying the name of an ELNEC file to open.Olderversions of EZNEC can also readand use files written byEZNEC 4.0. EZNEC4.0 uses the same plotfile format as EZNECv. 2.0 and 3.0, and can display plots saved by ELNEC or any version of EZNEC.

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

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

Where's the manual?

The manual is anintegral part of the program. With EZNEC4.0 running, In the EZNEC 4.0Control Center(themain window), click Help on the menu bar, then choose Contents to viewthe manual. You can also open the manual to the relevant topic frommanyplaces in the program by pressing F1.

Is it possible to geta printed manual?

Yes, if you're willing to printit yourself. If youpurchased EZNECon a CD-ROM, you'll find it in thePrintable Manual directory on the CD-ROM. Otherwise, you can downloadit. Clicking herewilltakeyou to the page where you can get more information. No pre-printedmanual isavailable.

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

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

Will EZNEC 4.0overwrite previous versions?

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

Will installing oruninstalling EZNEC erase or overwrite my existing description or tracefiles?


What's the differencebetween 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, independentprogram which doesn't require any other program or older version inorder to install or function.The only difference between a new purchase and an upgrade purchase isthe price; the program is the same.

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

The installed programis exactly the same -- theonly difference is in the format of the files used for installation.The download product is a single executable file, for convenientdownloading. It expands and creates temporary files during theinstallation process, which are deleted when the installation iscomplete. The CD-ROM contains several files. Onceinstalled, the programs and disk space requirements are identical. Youmay need to re-install EZNECin the event of a hard drive failure orchange to your computer system, so you should always keep either theCD-ROM or downloaded file. If you don't have any way to back up thedownloaded file on some medium other than your primary hard drive, youshould order the CD-ROM (with or without the download) to protectagainst loss of the program in the event of a hard drive failure.

My EZNEC v. 4.0 runsextremely slowly. Why?

Some versions of McAfee Antivirus sofware, when runningin the background detection mode, can cause extremely slow operation ofEZNEC v. 4.0 calculations. Thisproblem can suddenly appearwhen theantivirus software is updated. Apparently, the antivirus softwareintercepts and analyzes the communications between the calculatingengine and the main program. These communications are numerous andfrequent, so the rather slow analysis process by the antivirus programgreatly slows EZNECoperation. The only certain solution is to disablethe background checking feature of the McAfee software while running EZNEC v. 4.0. So far, thishas been reported only with McAfee version 4, and it appears thatversion 6 and later versions might not have this effect on EZNEC.Thisisn't certain,however. Other virus-detecting software could possibly have a similareffect, so if you encounter exceptionally slow operation, try disablingany anti-virus software you have running, and let me know if itsolves the problem.

What is dwspy36.dllin the EZNEC program directory?

Some people have expressedconcern about dwspy36.dlland wonder what its function is. This file is a "subclassing" control,part of a third-party utility package called SpyWorks, purchased fromDesaware, a highly respected company which is well known to the VisualBasic programming community. This package allows functionality beyondthat provided by Visual Basic or normal Windows programming but despiteits rather sinister name is not "spy" software. When you attempt toreduce the size of graphical windows below a certain point, EZNEClimitsthe minimum size. This size limiting isn't possible with Visual Basic(except with "bounce-back" type operation), so a technique called"subclassing" is used. EZNECinterceptsthe normal Windows message sentwhen a window is resized and directs it to code that limits the windowsize. The SpyWorks control (dwsbc36.ocx, which uses dwspy36.dll) allowsthis functionality. (It'sapparently so namedbecause of its ability to "spy on" -- intercept -- messagessent to and from the Windows operating system by applications duringnormal operation.) Some versions of EZNECinstalleddwsbc36.ocx and dwspy36.dll in the EZNECprogramdirectory; other versions installed them in the Windows systemdirectory instead. An increasing number of spyware removal programsmisidentify dwspy36.dll as spyware and delete it, which caused EZNECto crash.Because of this problem, EZNECwas modified at version 4.0.5 to use a recompiled version of a similarDesaWare product, rather than dwsbc36.ocx and dwspy36.dll. V. 4.0.9 andlater use an entirely different and newly compiled control. If you haveany EZNECprogram type of version 4.0.5 or later, you can safely deletedwsbc36.ocx and dwspy36.dll from the EZNEC program directory if they'rethere. I don't, however, recommend deleting them from the Windowssystem directory because some other legitimate application might beusing them.
No version ofEZNECdoes keystroke logging or any other type of user activityrecording, reporting, or Internet connection. For more informationabout the SpyWorks package, seehttp://www.desaware.com/SpyWorksL2.htm, and for more information aboutsubclassing, see http://www.desaware.com/Subclassing.htm.

>What language isEZNEC 4.0 written in?

The interface portion of theprogram was written inMicrosoft Visual Basic 6.0. It consists of more than 50,000 lines ofsourcecode, not counting comments. I wrote every line, and it took about twoyears of essentially full time work to develop the first Windowsversion. Thecalculating engine is a modified version of the public domain NEC-2program. It's written in Fortran, and incorporated as a separateexecutable file.

Where can I get more EZNEC models?

The CD included with the 20th and latereditions of theARRL Antenna Bookhas severalhundred EZNECmodels of a wide variety of antennas. While specially created to workwith the EZNEC ARRLprogram which also comes with the AntennaBook, they're also standard EZNECfileswhich work normally with EZNEC 4.0and EZNEC+4.0. Evenwithout the EZNECfiles, the ARRL AntennaBookis a bargain, but the files make it even more so. Also, check http://www.cebik.comfor models andother good information.