avast 4.7 home addition

Just installed Avast today, running Win XP Pro each time I reboot system it does a complete scan before it boots up to user page, this takes 45-60 minutes is there a way to bypass this feature? Thanks

Every time, or just once? It should run it only once.

It ran twice for me so was asking before I shut down again, it did not run on the third start up, I think there is a saying “the third times is the charm”. have shut down several times now and has not run again. Thanks for info.