Starting Windows 98SE in MSDOS mode

[mike2002]

When I restart in MSDOS mode, all I get sometimes is the flashing cursor and nothing else. No usual Windows mesage, and typed text does not register.

I do get a message at bootup that I have an invalid setting in the MSDOS.SYS file, but this does not appear to be the cause (or is it?).

I have a program that erases the Windows Swap file; it automatically restarts Windows in MSDOS mode, then gives a visible rundown of the number of erasing passes as it proceeds.

Sometimes it works OK, whilst other times all I get is the flashing cursor.
The programs helpfile tells me to restart Windows manually in DOS mode if it doesn't start automatically. But it makes no difference - it's the absence of the text that's the problem.

For all I know, maybe it IS working OK, just that there's no visible text telling me so.

Mike

[Paleo Pete]

If you have an invalid setting in MSDOS.SYS that most likely is the problem. MSDOS.SYS is one of the three system files necessary to boot a computer, (command.com and io.sys are the other two.) In reality, only command.com is absolutely necessary, but the only use for booting that way is to prove the machine will boot.

If you have an invalid setting in MSDOS.SYS chances are the machine won't boot, which is what appears to be happening. I'm not too familiar with what is supposed to be in that file, but an educated guess is that the program you referred to has re-written a PATH statement or done a sloppy job of adding a parameter. When the machine hangs with no command prompt DOS is looking for something that's not there or has been corrupted.

Another possibility is that the program itself has hung up, possibly by not being able to access conventional memory (the first 640K). If DOS and other drivers are loaded first, and you have 64K left over, for instance, and the program requires 96-128K to run...

The other scenario is a bit more complicated. Programs using conventional memory in DOS mode load in blocks, 64K per block. If a program is smaller than 64K it still uses a 64K block, and the rest of that block is not available, period. This is usually related to the upper memory area, the 384K above the original 640K conventional memory Bill Gates once thought would be "enough for anybody"...So you can still have memory unused, but not available, because some small driver has set up housekeeping in a certain memory location and not used the entire 64K available space. Nothing else can use that area...

Without seeing the contents of the MSDOS.SYS file in text form we would be fairly unlikely to be able to figure out what the problem is. Since it is basically a text file to begin with, it's no problem to view it n text form, but it is also hidden and read-only. That is to lessen the chance that inexperienced tinkerers can edit it and cause major problems.

It sounds like more likely a faulty command in MSDOS.SYS than a memory issue, but the two could also be related, in that the faulty command could be trying to tell the program to use memory that is not available. When that happens DOS has no way of telling you...it can't load, so it just sits there sticking its binary little tongue out...in the form of that blinking cursor... http://www.PCGuide.com/ubb/biggrin.gif

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[mike2002]

Mmmm, it's all a bit complicated for me. Curious thing is - it does work
at times, but not others. How do yoiu explain that?
Another query, is it possible to look inside the win386.swp file.
(Windows swap). I can Copy it, but it refuses to let me Paste it anywhere at all, floppy, zip, etc., and tells me that there is a file sharing
violation.

[iisbob]

The swap file is capavle of being read, you need a special binary dump reader to acces it tho-similar to the one used in NT troubleshooting.

Basicly, the swap file is the contents of a file that was " moved " out of volitile memory to make space for another file loading-this is why an increase in your RAM provides such a boost to Window's operation, it gives it more " room " to house the needs of running programs. Your swap file is the virtual RAM needed by window's to keep juggling the running applications, when windows' 95 first debutted-having more than 32 MB's of memory on a desktop was not usual, 8 was considered good, 16 as awesome!

The reason you can't move the swap file around in window's is because it's using it all the time-unless you turn it off or use a command in the system.ini file to limit it's use. If you have more than 128MB's, you can get away with turning it off-but i don't recommend it, instead just reduce it's size to say something around 64 MB's so that if you do need it, you still have it.

Right click on your MSDOS.sys file and uncheck the read only properties ( you'll also have to enable viewing of hidden files in folder options first ), then open notepad, browse to the root and select the MSDOS.sys file. this will open it in notepad, copy all you see there and then paste it here in a post-this will give people here a chance to examine it and help determine the possible problem. http://www.PCGuide.com/ubb/smile.gif



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iisbob

Computer-Show me the Enterprise; no bloody A, no bloody B, and no bloody C-just the original...Mr Scott { from a STNG episode }

[mike2002]

At last - have discovered why MSDOS mode works sometimes but not others.
Zone Alarm was the culprit!
I have to close Zone Alarm before I Shut Down, otherwise Windows hangs on the 'Windows is now closing down' screen. The same happens if I go into DOS mode without first closing Zone Alarm.
Re: the Windows swap file. Mine weighs in at 68Mb, both before and after I use a program that erases the file. Someone told me how to delete the following instruction to Enter after rebooting to a command prompt:-

cd c:\windows

del win386.swp

win

Thanks for the information anyway.
Mike

[Sylvander]

Hello mike 2002

Why on Earth would you want to delete your swap-file, and why would you want to look at it's contents.

The swap-file is a part of the "memory" higherarchy
i.e.
Primary Cache
Secondary Cache
Random Access Memory
Swap-File.

Would you wish to delete or study the contents of any of the others?

Your PC is constantly moving data around between these four locations depending on which data is in greatest demand. The data in greatest demand goes higher up the chain [and closer to the processor]; the data in least demand goes lower down [and farthest from the processor].
The default arrangement for swap-file use is that it is on the c: drive and the size required is constantly being calculated by a program and the file is resized to meet the predicted size requirement.
This file is normally dynamic [constantly changing] and the information in it would be meaningless [certainly to me].

You can,of course, change the location of the swapfile and by making it a fixed size, free the processor from the task of calculating it's needed size, and thereby reduce the load on the processor.

[mike2002]

Hello Sylvander,
What can I say?

This all came about as a result of downloading a File erasing program which, among it's features, is a function to erase the swap file.
I quote from the 'help' page: "This file may possibly contain sensitive data, and it persists even after you have shut-down Windows. For this reason, if you require tight security, you should opt to clean the Window's swap file."
I don't really need this function, but was curious to know why it wouldn't run.
Regarding deletion of said file, I found the following on 'Lycos Help & How-To':

Delete Windows Swap File
No matter how much memory you have installed in your system, Windows maintains a swap file on your hard drive, so memory contents can be "swapped out" when necessary. To find yours, select Start / Find / Files or Folders, to start the Find utility. Search your main system disk for *.swp files. Usually it is in the Windows directory and the file name is WIN386.SWP. The contents of this file can get fragmented over time, similar to the fragmenting of a disk drive.

Some defragment utilities, like Norton's, include software to defragment the Windows swap file. This really isn't necessary, because no important information is saved from one run of Windows to the next, and every time Windows starts it creates a new swap file if there is none. So all you need to do is delete the swap file occasionally. To delete it, you need to start by shutting down Windows so the swap file won't be in use. (Etc etc).

Mike

[Sylvander]

Hello again Mike 2002

QUOTE
1. "no important information is saved from one run of Windows to the next"
2. "This file may possibly contain sensitive data, and it persists even after you have shut-down Windows."
Two conflicting statements from those with vested interests?

I really cannot imagine anyone having concerns about the security of the contents of the of the swap-file. Even those charged with national security. Or maybe they are the only ones who would.

ANOTHER QUOTE
"Some defragment utilities, like Norton's, include software to defragment the Windows swap file. This really isn't necessary....all you need to do is delete the swap file occasionally."

Just picture data constantly on the move between Primary Cache, Secondary Cache, RAM and swap-file and the contents of the swap-file constantly changing. I'm sure it does become fragmented but I imagine that it reaches a limit where it ceases to increase.
If you wished to effectively counteract fragmentation of the swap-file you would probably need to be defragmenting every second or so.
I take it that they suggest deleting the file now and again as a more practical solution.
Hmmmm, I wonder!!!!