I have always heard about firewall since I started using computer but till today I am not clear about what it really does.

If you can explain about the firewall in windows operating system, I would be delightful.Thanks.

I want to make a site where the visitors would be able make their own profile. I have made registration system but I can not go anymore. How can I make it with PHP and MySql?

I would like to ask about the ASCII code and also the Hexadecimal code.Where are these code mostly used and is there any

alternative to these codes?

Microsoft Windows Error 1621 will be attributable to the particular Home Windows Installation software Service certainly not operating effectively.

This particular mistake is most probably attributable to how one's body may often have problems or maybe issues with their documents, and may consistently stop your system through to be able to access the actual documents instructed to purchase a software program to your process.

Fortuitously, we have an approach to stop that being an issuing – that's usually defined in this tutorial.

Error:

The Windows Installer Service could not be accessed. This can correctly installed.

Contact your support personnel for...

I have a .exe file that I need to execute, I typed in the required password and then I can open the files needed. But one time it happened that I typed the password incorrectly for three consecutive times. Since then I cannot open the .exe file and always gives me an error that says my password was invalid. If I open the same file in another computer, it will open without problems. How can I correct this error? I posted the screenshot below.

I use metadata in every page but actually I really don't know what it is.

That is why, I would like to ask here that what is a metadata and what type of information is stored in it?

As, adsense is becoming more and more popular daily. I would like to know why is it popular and the most convenient way to make account on it and start making money.

Please suggest some ideas.

Which is the best Graphical User Interface (GUI) software under  WYSIWYG for designing a website? As I am trying to develop

 a website, I would like to put my hands on the best and easiest software.Please suggest some softwares and also why is it the

best software.

I used Windows 7 and I enabled Aero but the themes and everything remains unchanged. I tried to adjust the colors and translucency but I still cannot change my active windows into anything distinct. Can someone please help me? It really doesn't matter if I need to edit the registry or do some modifications. I posted a screen shot of the two types of window wherein the left picture is the active window.

I can not change my font style. I went to control panel then fonts and clicked on the fonts, there was an option "done". I clicked on "done". But it is not working. How can I change the font style?