I keep getting this error. I've swapped memory modules, formated hard drive, tried different versions of DOS, cleaned the SIMM sockets on this clone 486sx 4Mb Ram. I've edited the config.sys file til blue in the face. Here is the exact error message: ERROR: HIMEM.SYS has detected unreliable memory at address: 00100000h. XMS driver not installed. Also MSD does not report any extended memory although I have 4Mb. Can somebody help?

I'm not sure how that memory thing really works, but as far as I'm concerned that part of your memory is screwed. Type help at DOS prompt, read the info on himem.sys, there might be some help in that. Does your computer load emm386? Could try that, beyond it I donno much.

I've gotten this error because of conflicting commands in the config.sys before. Try putting rem before each line in your config.sys except rhe line device=himem.sys and temporarily rename your autoexec.bat Also tye booting from a floppy disk made on a working computer with himem.sys specified it the bootdisk's config.sys to ensure your system files aren't damaged. Iff there is no change and you get the error even when booting from the disk, something is physically damagd in your computer (either motherboard or memory itself) If you are lucky and something I've mentioned stops the error, let me know and I'll help you resove your problem.

Also, I don't recommend it, but placing /testmem:off after the device=himem.sys line will do exactly what it says, it wont test your memory. If you use it, expect system crashes and perhaps data loss, but if you are just trying to use some old computer you have salvaged, it's a possible solution.

Hi, Usually such message mean you really have bad SIMM modules. I'm not sure what you mean by swapping. Did you swap memory modules with new ones, or you just swap modules beetwen two sockets?. In the last case you need to replace your SIMMs (at least one of them). But if you already tried to replace SIMMs with new ones and still had the error, then the cause can be in BIOS settings. All BIOSes has "Load Defaults" item in setup menu. Try to load defaults values for BIOS parameters. Sometimes memory give the error because too fast timing is set in BIOS. Good luck, Igor M

Sounds to me like you have an un-matched memory set. If you are using 72-pin memory ( which Im sure you are, since you wouldnt get this with DIMMS)you must have a matched set or you will get this error. I had a machine that had 2 16mb SIMMS in it, but they were not matched and I kept getting this error until I switched them. Also, some motherboards dont like it when you have gold plated memory and silver plated SIMMS runing together, it will also give you this error.

I have developed the same problem, Help! I have tried T H R E E sets of ram and all have the same memory error message???? This can't be something as simple as bad ram. I have re-installed dos 6.22 twice. Help or I kill the computer.