<<When I first bootup,it takes abot 5or6 minutes...>>
I believe this is perfectly normal, at least on my systems.
I don't time my system...but I do know that an approximate 3-4 minutes will pass from the time I press the power button to system functionality is turned over to me.
I assum that this is due to normal file loading, firewall, etc. and I think that my firewall will not allow activity to proceed on the system before the "all clear" has been sent to the system.
The more items loading/running at startup, the more pronounced the interval from boot initiation to desktop manipulation...so I would take a look at the items which you are loading at startup.
Any scanner of any sort which you have configured to run...will be among those startup items, as well as any other programs which have thrown a startup item in when the program was installed.
One tool for managing startups: AutoRuns for Windows - http://technet.microsoft.com/en-us/sysinte...s/bb963902.aspx
The items that you want to look at will be on the Logon tab, do not look at any other tabs.