Last Revised
AST RESEARCH, INC.        TECHNICAL BULLETIN # 1734          07/01/97 
 
 
 
TITLE:  Adaptec 7800 & Missing Operating System
 
 
ISSUE 
 
   When the user attempts to install NT(version 3.51 or 4.0) on a 
   system that is using the Adaptec 7800 controller, under some 
   circumstances, Windows NT will complete the first phase of the 
   setup, but it will fail when rebooting into Graphical User 
   Interface (GUI) mode, displaying the following error message: 
   
             'Missing Operating System'
   
   This issue affects all Manhattan D systems. 
   This issue was duplicated on system p/n 503223-202.    

 
BACKGROUND 
 
   This is a known issue with Microsoft Windows NT, and it is dealt 
   with on the Microsoft Knowledge Base as Article ID Q143141.    

 
ACTION 
 
   Prior to installing Windows NT, perform the following two 
   actions:
   
   1. Set the 'Extended Translation BIOS' for hard drives 
      >1GB = DISABLED under the Adaptec BIOS Setup.
   
   2. Create and format a partition on the boot logical 
      drive, using MS-DOS or another operating system.
   
   Upon a successful installation of Windows NT, reset the 'Extended 
   Translation BIOS' for hard drives >1GB = ENABLED under the 
   Adaptec BIOS Setup.    

 
NOTES 
 
   N/A    

 
TAN EPR 600TJ 
 
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