Windows 95 requirements l 80386DX or higher machine l at least 4 MB of RAM (8 MB recommended) l mouse l VGA or better monitor l hard drive with at least 20 MB of free space

Installing Win95 over 3.x l 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

Installing 95 in own directory l If you install Win95 in new directory, you can preserve the old DOS or Windows environment. l To boot to both operating systems, must configure the system with dual boot options. l How do you configure a dual boot? » Set MSDOS.SYS file’s BootMulti= 1

Windows 95 core files: l KERNEL32.DLL and KERNEL386.EXE » contain Win95 core and load device drivers. l GDI files provide graphical device interface l USER files provide the user interface. l WIN.INI included for compatibility with older 16-bit software. l Can use SysEdit to edit SYSTEM.INI, PROTOCOL.INI, CONFIG.SYS, WIN.INI, AUTOEXEC.BAT (Start/Run, type “sysedit”).

Windows 95 registry l Configuration information in Win95 is stored in the registry, located in WINDOWS/SYSTEM folder l Registry takes over many of the functions of SYSTEM.INI and WIN.INI files l Can be viewed and edited with regedit.exe l Each time Windows boots successfully, existing registry files are backed up with DAO extension

Registry Keys: l Hierarchical organization of 6 keys: » HKEY_CLASSES_ROOT » HKEY_CURRENT_USER » HKEY_LOCAL_MACHINE » HKEY_USERS » HKEY_CURRENT_CONFIG » HKEY_DYN_DATA l Know what each one of these does!

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

Windows 95 memory l Swap file in Win 95 called WIN386.SWP » initial size set automatically by Windows » can change size in Device Manager/Performance/Virtual 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 l CONFIG.SYS is necessary only if you have 16 bit device drivers

MDDOS.SYS l In Windows 95, this is hidden, read-only located in root directory of boot drive l used for startup options l See Meyers for options you can set here l Most important: » BOOTMULTI=1 to boot other operating system

File Allocation Tables (FAT) l FAT indexes hard disk contents and files l Windows 95 (a) uses FAT16 l OSR2 - Windows 95(b) - supports FAT32 l 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

More about Win95 l Windows 95 supports VFAT- Virtual FAT » 32-bit Protected-Mode FAT File System » provides support for long file names l Windows 95 doesn’t use SMARTDRV disk caching utility - replaced with VCACHE, a protected mode drive

Windows 95 boot process l Win95 initially starts in real mode, loads any 16-bit legacy drivers, then switches to protected mode for 32-bit operations l Five phases of boot process: » Phase 1Bootstrap with the BIOS » Phase 2Loading DOS drivers and TSR files » Phase 3Real-mode initialization of static virtual device drivers (VxDs) » Phase 4Protected-mode switch over » Phase 5Loading of any remaining VxDs

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

Win 95 Boot Modes l Normal mode -loads all normal startup and Registry files. l Logged - Normal mode, but system maintains an error log file that contains steps performed and outcome. (BOOTLOG.TXT) l 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

Safe Mode » Bypasses several startup files - particularly, the Registry, CONFIG.SYS, AUTOEXEC.BAT, and the SYSTEM.INI’s [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 /d:m at the DOS prompt, or by pressing the F5 function key during startup.

Windows 95 features l Plug and Play support l Filenames up to 255 characters l 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.

Suggestions... l 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. l 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

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 won’t 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)