A virtual server is basically a partitioned  drive on a main server.  Multiple virtual servers can be created from a single server which would have capabilities  of acting as a separate serve altogether i.e. a virtual server can be run  full operating system as well as be rebooted without affecting other virtual servers. First, the physical server booted in normal manner. Once the boot process has been completed, a program is executed which boot all virtual servers at the machine.Virtualization can be of two types:

1.Software Virtualization

2. Hardware Virtualization

The first one, Software Virtualization, is mainly used for web hosting services wherein the same kernel is used.In hardware virtualization , hardware resources are partitioned accordingly. virtual private servers are mainly used for security purposes. For instance, if you require installing of a software that might have bugs, It would be wise to install and test it on a virtual server so that the main server is not effected in case it contains any bugs.

This is an application used to alert when you have new messages in your email. It supports only windows based operating systems. It is displayed as an icon in the startup tray.It shows the preview of the messages as and when it comes without logging in to the browser. Just follow the below steps to easily check your e-mail.

1. Download the software from the following location. Size is just 292 KB.
http://toolbar.google.com/gmail-helper/notifier_windows.html

2. Install the software in to your PC. While installing, it will display two options named Run on startup and Use for Outgoing mail. Select both the options.

3. After the installation is completed, it will ask to enter the username and password of your gmail account. Enter the details.

4. Once the details are entered, the icon appears on the system tray and shows the preview of the new messages.

5. Now you have to select the browser in which you want the messages to be showed. Right click the icon and select 'Options'. It will show the list of browsers if you have more than one. Choose the desired browser.

6. To read the mails, right click the icon and click the option 'View Inbox'. It will open your gmail in the browser you have selected.

The preview of the messages appears like the image below:

DHCP is an acronym for Dynamic Host Configuration Protocol. once a range of IP addresses has been defined on a DHCP server, it will automatically assign them to computers connected to the network. this is done once the system is started and recognized on a server. First a broadcast request is sent by the client to the DHCP server. this message sent is known as DHCP DISCOVER. the router will then send a packet to the DHCP. once a pocket is received,an IP address is   sent to the client based on certain rules that are set on the server. this IP address is then reserved and an OFFER request is sent to the client. later the client sends a REQUEST packet to acknowledge the IP address. lastly a confirmation packet known as DHCPACK  is sent by the server to finalize the IP address for the client.

This IP adress may expire after a certain period of time as set by the DHCP server.

This method of IP configuration is used to make configuration easier by avoiding IP address conflicts

The most commonly used browsers are Internet Explorer, Mozilla Firefox and Google chrome.But there are many unpopular freeware browsers which are equally good when compared with these standard browsers. May be the viruses and other problems may not attack when we use unpopular browsers. Let us see some of such browsers below.

Arora
It is a cross-platform web browser. It runs on almost all operating systems supported by the Qt tool kit like Linux, Mac OS,Windows etc. It is an open source software. It can be used to prevent pop up advertisemts and help users work in privacy mode. It has got all the basic features that are needed for a browser. It is built with the same technology as google chrome.It can be downloaded from the following website.
http://code.google.com/p/arora/

Flock
This browser works similar to Mozilla Firefox. So this will be very easy for the the users of firefox. It runs on the widely used operating systems like windows,linux, Mac etc. It has got most of the features provided by firefox. It is the best browser for working with social appliations like faceboox. It can be downloaded from the following website.
www.flock.com

K-Meleon
It is a light weight web browser. It runs on windows based operating systems.It is designed based on the Gecko layout engine. It is an open source software licensed under GNU. It is available in following languages : English,German, Spanish,French,Polish,Russian. The size of this browser (5.8MB) is also very less when compared to other browsers. This browser can be downloaded from the following website
http://kmeleon.sourceforge.net/

Maxthon
This browser is also designed to work with windows based operating systems. It is a tabbed browser with fast switching of the tabs. It has got the Ad hunter facility which allows to block pop up windows and advertisements. It supports more than 25 languages including Arabic,Chinese,Japanese,Italian,Swedish,Thai etc. This browser is very popular in China. It was first introduced in 2003 and has got many awards from the leading technolocy magazines like PC world, Chip online etc. The size of this browser is 6.4 Mb.It can be downloaded from the following link.
http://www.maxthon.com/download.htm

PaleMoon
It is said that the speed of this browser is 25% more than that of the widely used browsers like firefox,chrome,IE etc. It runs only on windows based operating systems. It uses the same technology as firefox. It is built with the necessary features of firefox and not all.It supports all firefox extensions,add-ons etc. It is also portable and it can be stored on a pen drive and can be used in any system with all the settings we created. It supports processors like Pentium IV,Pentium D,Celeron -D etc. It can be downloaded from the following website
http://www.palemoon.org/download.html

Avantbrowser
It is said that this browser is the fastest of all browsers. It is possible to see multiple websites simultaneously using this browser. It has full compatability with all functions performed by internet explorer. It has got built-in AD/Pop-up blocker which eliminates unnecessary advertisments and pop-up windows.It also has got built-in RSS reader. This is a good alternative for IE. It can be downloaded from the following website
http://www.avantbrowser.com/download.html

Caymon browser
It supports windows 98,2000,XP and millenium editions. It has got multi window browsing feature. It can block all flash animation advertisments with the single click of the mouse. It has got multi language translation facility through which the web page can be translated to many languages. It has got built-in pop killer which blocks pop up windows. With this browser, it is possible to read a page in 10 different languages. It is faster than internet explorer. The download size of this browser is very less ( less than 2 Mb ).This can be downloaded from the following website.
http://www.caymanbrowser.com/download.html

Crazy browser
It is a free browser for windows. It supports tabbed browsing . It has built-in ad blocker, customizable mouse gesturen and supports commonly used plug-ins. It is available in many languages like arabic,greek,swedish,hungarian etc. It can be downloaded from the following website
http://www.crazybrowser.com/download.htm

Deepnet explorer
It is the first browser to introduce RSS reader in it. It has anti phishing alarm facility which warns the user when any fraud website is encountered.It also has got popup killer,content filter,mouse gesture etc.It is fully compatibile with IE and automatically imports the settings from IE. It is possible to set several pages as start up pages. It runs on windows based operating systems. It can be downloaded from the following website
.http://www.deepnetexplorer.com/download/download.asp

GreenBrowser
It is also developed for windows based operating systems. It has got Ad filter for filtering advertisements. It also has mousegesture,content filter,popup killer. It has got speed dial feature through which can set the most used websites we use ( just like the speed dial option in mobiles ). It is possible to create shortcut keys for the commonly used functions. It also has got page manager where it is possible to view the last visited pages. It supports multiple languages like arabic, chinese,french etc. This software can be downloaded from the following website.
http://www.morequick.com/Download.htm