virtualbox.org

when i try to open dos promot full screen it stuck the copmuter
it opens 2 windows instead of one full screen

I guess you mean that it opens two virtualbox windows? That would be because two screens are configured in the VM settings.

how do i change it i didnt find where to change?

If this question is about a DOS VM then it's very badly worded. "DOS prompt" refers to the command.com application in DOS based OS's, and the Cmd.exe app in Windows NT is also sometimes incorrectly referred to as the DOS prompt. I read the question (including info from the title) as "I have a Win7 guest, I tried to open a command prompt window and two terminal windows open". And as that sounds like a guest OS issue I ignored it.

Questions need to be worded clearly if you expect accurate help. Posting the question in a relevant forum could help too, i.e. why ask about a DOS VM in the "Windows Hosts" forum?

Ok i will ask again
my host is win 7
my guest is win 2000 or win 98
when i try to open dos full screen it doesnt open
what can i do

TTYT wrote:my guest is win 2000 or win 98

Those are very different guests! The DOS prompt in Win98 really is 16 bit DOS, run in what is effectively a VM. In Win2k the "DOS prompt" is actually the command console, a 32bit text mode application. Are you saying the symptoms are the same in both cases? Because frankly I doubt that can be the case: I've heard people report problems about 16bit apps before, but there's no way the command console can be affected that way even if it does look roughly similar.

TTYT wrote:when i try to open dos full screen [in Win98] it doesnt open

I added the "[in Win98]" myself, since I suspect is what you really mean. Win98 is not a supported guest OS, and I believe one of the fundamental reasons for that is that it contains a mix of 16bit and 32bit code, and 16bit code is hard to virtualize in software alone. In particular I seem to recall that the display drivers may not be fully 16-bit compatible. The problems are fixable but working on a fix for a dead OS is not commercially sensible.

TTYT wrote:what can I do

You might get better results if you enable VT-x in the VM settings.

ps. Moving this topic to the "Windows Guests" forum, since the host OS is not relevant to the question asked.

How can i enable VT-x in the VM settings
it doesn't give me to do it

I can't answer that without a VM log file (as a zipped attachment please). For details see Minimum information needed for assistance.

here what you asked

What are these logs? Neither seem to be for a Win98 guest, e.g. "2000..." is presumably Win2k, but the "666... " log shows guest additions installed so certainly can't be Win98. It shows only 16MB being allocated as VRAM, which seems low, and could cause graphics problems with a set display size as large as 1600x792 as appears in the logs.

The 666 logt also shows VT-x enabled and working, despite you saying the VT-x was not available to the VM.

Every new message seems to be either perfunctory, self-contradictory or to contradict info given by the previous one. I think I'm done here.