Windows 95 requirements

1
Windows 95 requirements

• 80386DX or higher machine
• at least 4 MB of RAM (8 MB recommended)
• mouse
• VGA or better monitor
• hard drive with at least 20 MB of free space

2
Installing Win95 over 3.x

• On a computer with Win3.x, you can install Win95
  in same directory, which will install it on top
  of existing Windows
• configuration information obtained from existing
  SYSTEM.INI, WIN.INI, and PROTOCOL.INI files and
  moved into Windows 95 Registry.
• Existing settings will work automatically when
  Windows 95 is first started.
• Existing Windows 3.x Group (.GRP) files imported
  into Registry

3
Installing 95 in own directory

• If you install Win95 in new directory, you can
  preserve the old DOS or Windows environment.
• To boot to both operating systems, must configure
  the system with dual boot options.
• How do you configure a dual boot?
• Set MSDOS.SYS files BootMulti 1

4
Windows 95 core files

• KERNEL32.DLL and KERNEL386.EXE
• contain Win95 core and load device drivers.
• GDI files provide graphical device interface
• USER files provide the user interface.
• WIN.INI included for compatibility with older
  16-bit software.
• Can use SysEdit to edit SYSTEM.INI, PROTOCOL.INI,
  CONFIG.SYS, WIN.INI, AUTOEXEC.BAT (Start/Run,
  type sysedit).

5
Windows 95 registry

• Configuration information in Win95 is stored in
  the registry, located in WINDOWS/SYSTEM folder
• Registry takes over many of the functions of
  SYSTEM.INI and WIN.INI files
• Can be viewed and edited with regedit.exe
• Each time Windows boots successfully, existing
  registry files are backed up with DAO extension

6
Registry Keys

• Hierarchical organization of 6 keys
• HKEY_CLASSES_ROOT
• HKEY_CURRENT_USER
• HKEY_LOCAL_MACHINE
• HKEY_USERS
• HKEY_CURRENT_CONFIG
• HKEY_DYN_DATA
• Know what each one of these does!

7
Registry files

• Registry files are USER.DAT and SYSTEM.DAT
• Each time the system succesfully boots, backup
  copies of the registry are saved as USER.DA0 and
  SYSTEM.DA0
• If Windows 95 starts and is missing either
  USER.DAT or SYSTEM.DAT, it will restore from the
  backup copy

8
Windows 95 memory

• Swap file in Win 95 called WIN386.SWP
• initial size set automatically by Windows
• can change size in Device Manager/Performance/Virt
  ual Memory
• default swap file setting in Win95 usually
  results in huge swap file size- much larger than
  needed- best to set to 2-3 times the amount of
  RAM in system
• CONFIG.SYS is necessary only if you have 16 bit
  device drivers

9
MDDOS.SYS

• In Windows 95, this is hidden, read-only located
  in root directory of boot drive
• used for startup options
• See Meyers 610-11 for options you can set here
• Most important
• BOOTMULTI1 to boot other operating system

10
File Allocation Tables (FAT)

• FAT indexes hard disk contents and files
• Windows 95 (a) uses FAT16
• OSR2 - Windows 95(b) - supports FAT32
• FAT32 features
• reduced cluster size (4K) compared to FAT16-
  resulting in much less wasted cluster size
• no limit to number of root directory entries
  (limit of 255 in FAT 16)
• FAT 32 stores 2 copies of boot sector, so if one
  copy is damaged, can recover backup

11
More about Win95

• Windows 95 supports VFAT- Virtual FAT
• 32-bit Protected-Mode FAT File System
• provides support for long file names
• Windows 95 doesnt use SMARTDRV disk caching
  utility - replaced with VCACHE, a protected mode
  drive

12
Windows 95 boot process

• Win95 initially starts in real mode, loads any
  16-bit legacy drivers, then switches to protected
  mode for 32-bit operations
• Five phases of boot process
• Phase 1 Bootstrap with the BIOS
• Phase 2 Loading DOS drivers and TSR files
• Phase 3 Real-mode initialization of static
  virtual device drivers (VxDs)
• Phase 4 Protected-mode switch over
• Phase 5 Loading of any remaining VxDs

13
Windows 95 log files

• Windows 95 maintains log files that track system
  performance and can be used to assess system
  failures.
• SETUPLOG.TXT logs bootup events
• DETLOG.TXT detected hardware devices
• BOOTUPLOG.TXT logs Startup procedure
• stored in the drives root directory
• All three are text files that can be viewed with
  any text editor

14
Win 95 Boot Modes

• Normal mode -loads all normal startup and
  Registry files.
• Logged - Normal mode, but system maintains an
  error log file that contains steps performed and
  outcome. (BOOTLOG.TXT)
• Step-by-Step Confirmation displays each startup
  command line-by-line and waits for confirmation
  before proceeding
• enables you to isolate faulty startup command
• press F8 key at Startup menu

15
Safe Mode

• Bypasses several startup files - particularly,
  the Registry, CONFIG.SYS, AUTOEXEC.BAT, and the
  SYSTEM.INIs Boot and 386enh sections.
• Loads keyboard, mouse, and VGA drivers
• If Win95 determines that a problem is preventing
  system from starting, it attempts to restart the
  system in Safe mode.
• Safe mode can also be accessed by typing Win /dm
  at the DOS prompt, or by pressing the F5 function
  key during startup.

16
Windows 95 features

• Plug and Play support
• Filenames up to 255 characters
• Troubleshooting and evaluation tools
  (Start/Programs/Access/System Tools)
• System Monitor tracks performance of system
  resources
• Resource Meter is a bar chart displaying percent
  usage of the System Resources, User Resources,
  and GDI resources.

17
Suggestions...

• The best way to prepare for the Windows 95
  questions is to actually work with the software-
  get familiar with the interface, know how to
  change settings, etc.
• For example, make sure you know
• how to configure virtual memory
• Device Manager/System/Performance/Virtual Memory
• how to change disk cache settings
• Control Panel/System/Performance/File System

18
More hands-on things to know

• where to edit the registry (careful!)
• Start-run-regedit
• how to make a boot disk
• Control Panel/Add Remove Programs/Startup Disk
• note that this wont keep a copy of the registry
  but a program called ERU.EXE on the Win95 CD will
  make an emergency recovery utility to enable you
  to save all important Windows files, including
  registry, to a floppy
• Where to troubleshoot hardware conflicts, etc.
• Device Manager (yellow exclamation point
  indicates conflict)