I am new-one in this forum.I am making a program for that purpose i want to know some information about windows please help me by providing this information.
My question is

1)I want to know the technical name of utility that run on boot time before login in xp.
For example....Avast Anti-virus boot time scan.
2)As Avast use their on utility.can i able to make my own.If yes then please tell me how i can make.

Thanks in Advance:)

Not wishing to be mean, but if you had any chance of writing a boot-time AV scanner you would not be posting such a question here. Leave it to Avast. The wheel has been invented... use your time doing something else.

oh,sir i am also implementing it but actually i did't know it's technical name.Kindly if u know tell me

I'm sorry, but I am not quite sure what you are asking....may i point out that there are several offline or boot-time antivirus scanners available? Boot scan, offline scan? Avast in their installable AV product have a setting which allows you to scan your system before Windows actually starts; Avira and Bitdefender have bootable cd products which perform an offline AV scan [again without Windows being started]. They are updated with new definitions continually/daily.
http://www.avira.com/en/support/support_downloads.html :: the Rescue System download.
-with both these tools you burn a cd from the iso. The Avira version is already fully updated when you get it, Bitdefender's will automatically update when started if a net connection is available.

What is the software you are implementing? What is the purpose of that software? What does it do? Why you are implementing it? I think we need more infor as to what purpose of that software before booting it to login. Are you talking about autoexec.bat or config.sys files?

Or perhaps i focused too much on your mention of an AV. Do you mean some utility that runs, say, in kernel mode before winlogon runs? Then I really am not sure... boot mode does me. [XP doesn't look at autoexec or config.sys].