If your computer has 1 gigabyte (GB) or more of random-access memory (RAM)
installed, Windows may not start. Also, when you try to start your
computer, you may receive the following error message:
Insufficient memory to initialize Windows.
Quit one or more memory-resident programs or remove unnecessary
utilities from your CONFIG.SYS and AUTOEXEC.BAT files, and restart
This behavior may also occur during Windows Setup, or when you try to
start Windows for the first time.
To work around this issue, add the following line to the [386enh] section
of the System.ini file:
This limits the amount of physical RAM that Windows can access to 768 MB.
(Hmm, better idea would probably be to look at
set MaxPhysPage to 3C000 for 960MB of RAM (1,006,632,960 bytes).)
Win98(SE)/Me systems with MORE than 1.5 GB:
Microsoft Knowledge Base (ID 304943)
"If your computer has more than 1.5 gigabytes (GB) of memory (RAM), the computer may reboot continuously when you try to start Windows Millennium Edition (Me) or Windows 98" (or 98 SE). Additionally, setup may hang. Solution:
To work around this issue, add the following line to the [386enh] section of the System.ini file:
This limits the amount of physical RAM that Windows can access to 1 GB.
A concern I have: AXCEL216's WinDOwS Tricks - Part 8
"Most 80386, 80486 and all Pentium class (and above) CPUs make use of RAM in 4 KB (4096 Bytes) pages. Newer Pentium II/III/IV and AMD K6/K6-2/K7/K8 CPUs use 4 MB (4096 KB) pages. That's exactly what "MaxPhysPage" does: limits the number of RAM pages available to Windows. This way you can tell EXACTLY how much RAM Windows accesses, and if THAT particular memory is defective."
says "There is no known instance of a computer successfully running Windows 95/98/Me with more than 1.5 gb of RAM, although a number of people have been able to do so with exactly 1.5 gb and many more have done so with 1 gb."
Apparently 1.5GB haunts more than Windows. http://www.freedos.org/ has news
dated April 22, 2004 which refers to "the recent freedos-devel discussion on XMSDSK with >1.5G machines."
If you have more than 2GB of RAM
Microsoft Knowledge Base Article - 181594
"If you install more than two gigabytes (GB) of memory (RAM) in your computer, you may be able to use only two GB of RAM in Windows 95." "Although Windows 95 has the ability to address up to four GB of virtual memory, it can access and use only two GB or less of physical RAM."
says that applies to Win 98 and Win Me as well. It's doubtful that any of these Windows could use more than 2GB if they are relying on HIMEM.SYS, and if HIMEM.SYS (at least in some Operating Systems, including Win98) is limited to 2GB which I believe is the case from various pieces I've read.
850 MhZ + breaks Win Me
archive of KB278844: “850 MHz or Faster Windows Me Computer May Hang
(from before Microsoft removed the KB article)
documents a problem:
“Windows attempts to estimate the computer's speed by reading the keyboard repeatedly for 55 milliseconds. However, the number of iterations may exceed 65,535 on computers with a very fast read character BIOS function and overflow the variable that holds the count.”
It refers to a fix which is a Winboot.sys that is dated 11/06/2000 07:56p
and is 110,080 bytes.
However, Winboot.sys is equivilent to IO.SYS. It is perfectly proper to
simply think of Winboot.sys as being an IO.SYS file that just has a
different name. A later version of IO.SYS has been released with
Hopefully that includes the code from KB278844 that casues a problem.
Here are some other notes I've made.
1MB is the maximum RAM the 8088 address bus can see. By contrast, the new Pentium 4 CPU has a 36-bit address bus (236 = 68,719,476,736, or 64GB) and has a 64GB RAM limit_in theory!
Let's look at the study model, an 8086 CPU. The 8086 has a 20-bit address bus and, therefore, can handle up to 1MB of RAM.
(maybe was supposed to link to the next line for WinMe data?)