what are digitally signed drivers

after the difficulty experience with the windows 2000 Microsoft has realized the importance of driver compatibility with windows.the hardware manufactured and then come up with there driver compatible with Microsoft operating systems.and they were tested at Microsoft labs.once a driver found compatible with Microsoft it was added with the CAB file as a digital signature.now when drivers installing into windows its looks for this CAB file.the drivers are proceeded if it founds digital signed,but otherwise there are 3 option of actions as below.

• ignore
• warn
• block
  

remote access service (RAS)

RAS was a service provided by Windows NT which allows most of the services which would be available on a network to be accessed over a modem link. The service includes support for dialup and logon, and then presents the same network interface as the normal network drivers. It is not necessary to run Windows NT on the client - there are client versions for other Windows operating systems.

A feature built into Windows NT that enables users to log into an NT-based LAN using a modem, X.25 connection or WAN link. RAS works with several major network protocols, including TCP/IP, IPX, and NBF.

for example

when the user needs to connect to the lan at the office time to time from remote location the RAS has to configured at the office.the RAS has attached to the modem and a fixed phoneline.once the remote user dials to the phone number of RAS using his dialup connection the RAS accepts the call and validate user credential.if the user is authorised he is allowed to connect to the office lan.

callback

in remote access,the callback option is allow the RAS to called back to the remote user once the account validated.there are 2 options,

• set by a caller

the remote user will be callback by the RAS to any number the user has called from.

• always callback to

in this option RAS calls back to a predefined number set under the user account.no matter which number the user calls from.

internet connection sharing (ICS)

Overview of ICS

If you have multiple computers, you can use ICS to allow you and others on your local area network (LAN) to perform different tasks simultaneously. For example, one person can send and receive e-mail messages, while another person downloads a file, and another person browses the Internet. You can also gain access to your corporate e-mail accounts from a client computer while others on your LAN cannot. With ICS You can use Web-enabled programs (such as downloading updates) as well as Microsoft NetMeeting and other video conferencing programs.

when ICS is enabled in the computer it also act as a DHCP,DNS,GATEWAY for the clients.The connection to the Internet is shared to other computers on the local area network (LAN). The network adapter that is connected to the LAN is configured with a static IP address of 192.168.0.1 and a subnet mask of 255.255.255.0 ICS can only be used in workgroup envirenment.

How to use Internet Connection Sharing

To use Internet Connection Sharing to share your Internet connection, the host computer must have one network adapter that is configured to connect to the internal network, and one network adapter or modem that is configured to connect to the Internet.

On the host computer

On the host computer, follow these steps to share the Internet connection:

• Log on to the host computer as Administrator or as Owner.

• Click Start, and then click Control Panel.

• Click Network and Internet Connections.

• Click Network Connections.

• Right-click the connection that you use to connect to the Internet. For example, if you connect to the Internet by using a modem, right-click the connection that you want under Dial-up.

• Click Properties.

• Click the Advanced tab.

• Under Internet Connection Sharing, select the Allow other network users to connect through this computer's Internet connection check box.

• If you are sharing a dial-up Internet connection, select the Establish a dial-up connection whenever a computer on my network attempts to access the Internet check box if you want to permit your computer to automatically connect to the Internet.

• Click OK.
  

You receive the following message:

When Internet Connection Sharing is enabled, your LAN adapter will be set to use IPaddress 192.168.0.1. Your computer may lose connectivity with other computers onyour network. If these other computers have static IP addresses, it is a good idea to set themto obtain their IP addresses automatically. Are you sure you want to enable InternetConnection Sharing?

• Click Yes.

system recovery (safe mode)

what is safe mode

when running in safe mode only the minimum required drivers are loading.this includes following.

• Vga with minimum drivers
• Floppy,harddisk and cdrom controller drivers
• Keyboard and mouse drivers

when run on the safe mode only the minimum required drivers to start the computer would be loaded in the boot up process.there for is possible to boot in the safe mode and remove any problematic hardware or its driver prevents the system from starting.

Getting to a Recovery Menu

Instead WinXP uses the combination of Safe Mode and System Recovery to effect repair of your WinXP installation. You also can try the "Last Known Good Configuration" boot option to try to restore your Windows XP system to a workable state if critical system files are not damaged.

To enter the location where these options are available restart your computer then press F8 right after the BIOS message disappears and again after selecting the operating system. You should see these below options.

• Safe Mode
• Last Known Good Configuration
• Start Windows Normally

Selecting these options will do the following:

• Safe Mode

takes you to a stripped-down version of Windows where only the most basic of Windows functions are available to help you troubleshoot your problem. You can choose System Restore in Safe Mode.

• Last Known Good Configuration
  

when changes made to a system during a session they are added to a registry setting called default configuration.these newly added settings to the default configuration will be added to a another register setting called Last Known Good Configuration.in instance or just after a restart and logon boot both default and Last Known Good Configuration are equal.

• Start Windows Normally
  

will load Windows in the regular fashion. If you were having problems last time you attempted to load Windows this option may not work.

system recover (ntldr missing)

The Windows XP CDs has a tool called the Recovery Console which can be used to repair errors that prevent Windows XP from starting using the command line.

• Insert the Windows CD and start the computer.
• When the Welcome to Setup screen appears, press R.
• Type a number corresponding to the Windows installation you wish to repair (this means windows partition,usually 1) and press Enter.
• When prompted, type the administrator password and press Enter.if there is no password leave it blank and press Enter
  
• From the command prompt, copy NTLDR and NTDETECT.COM from the i386 folder of the CD to the root folder of the hard drive. In the example commands given below, C: is the hard drive and D: is the CD-ROM drive. You will need to change the drive letters if appropriate:
  COPY D:\I386\NTLDR C:\
  COPY D:\I386\NTDETECT.COM C:\
• Remove the Windows XP CD from the drive and restart the computer.

Your ntldr missing problem will be solved

bootup process of windows

the process which happens from the time the computer is switch on to the time user logon is called as bootup process.

steps of bootup process

• preboot sequence
• boot sequence
• kernal load
• kernal initialization
• logon

preboot sequence divided into 3 steps

• post (power on self test)
• MBR (master boot record loading)
• nt loader (ntldr loading)
  

print devices (printers)

the print device is a hardware device that is used to take the hard copy of the document.

local printer

when the print device is physically attached to computer it becomes a local printer for the particular computer.

network printer

a shared print device which could be accessed by the client of a network is called as a network printer.

print server

a computer which is physically attached with a print device and also dedicated to control print related activities.

requirement of a print server

• higher harddisk capacity
• higher memory capacity

print drivers

a software interface between the print device and the operating system called as print drivers.

print spooling

in windows when a print job is added to the print que .its automatically and temporarily saved to the harddisk.this is calling spooling.