Issues booting up, trouble with isolating...

Hello all,
First of all I am new to the forum and I'm glad to be here, hopefully you will be able to help me solve my problem!
The build that the issue concerns is the one I have specified in my profile, it is my first build for myself and my first Windows 7 build. I finished almost a year ago, but recently I've noticed a huge delay after the "Starting windows" screen that happens only occasionally. I would go through and do a clean start, think I've isolated the problem program and then Windows would start normally. But then the next time I go to boot up, it takes a minute and a half! I have no idea where to go and everything I've read online has been sort of misguiding. If you need any more info let me know! This is starting to drive me nuts. I've spent more time trying to figure it out than I ever would have waiting for my computer to boot longer, but it has to be perfect

Try booting in to safe mode and see if that makes a difference.
While you're in safe mode, run a virus scan and also run CCleaner CCleaner - PC Optimization and Cleaning - Free Download
If that doesn't resolve it, check if your harddrives are heavily fragmented, and make sure the C drive isn't almost full.

Work through these Troubleshooting Steps for Windows 7 including the hardware tests.

The steps check over everything, lead up to if necessary getting a perfect Clean reinstall which should resolve the problem if hardware tests OK.

You can also normally find the cause for slow startup by Gathering a Startup, Shutdown, Sleep, Hibernate, or Reboot Trace - Windows 7 Forums

Everything was pointing toward software causing a problem at boot. Updated the firmware on my Crucial M4 and my graphics drivers and it boots right every time. I'm thinking it was ATI catalyst or some BS.