yes you can tell it in the options, start at windows start up.
click on options, Choose Run at windows Startup.. make it a green check mark.
Personally i moved on from Ad-aware to a company called WEBROOT.
It is called Spy Sweeper...
They make a nice clean Spyware package. It works great. I recived a free copy from a seminar i sat in with them, yes you have to pay for it on a subcription basis, but spyware will soon be ran like virus scan software so get used to having to pay for something...
Ad-aware works great though.. and yes it is still free... for now...
someone else mentioned before they use a combination of a few products, i think that is the best idea... download a few different ones and run one every few days.
but that is getting off the topic as to why XP is booting slow...
sorry..