Computer takes 2 minutes to boot up at the XP splash screen...HELP?

I have an IBM thinkcentre s50 desktop. and i have never had this problem til yday. When i boot up my computer, it boots fine up to the XP splash screen. it takes about a minute or two before it takes me to the login page. I have done basically everything. i ran ccleaner, changed my boot option to ';noguiboot'; (which takes the same, long boot time except its blank). i want to know how to fix and resolve this issue..Please help me.Computer takes 2 minutes to boot up at the XP splash screen...HELP?
I am pretty sure there is mention of ';hangs at bootup'; on one of the XP tweaks links on my web page below