Why Computer is so slow after boot?

Question

This situation has happened to me multiple times and I've tried to diagnose the problem unsuccessfully. This has to deal with my work PC.

Machine/Software Specs:
Windows 7 x64
32GB Ram Core i7 (ivy bridge class).

I've had my PC rebuilt multiple times throughout the years but this problem always seems to come back. Initially my PC will boot relatively quickly. Over time it will slow to a crawl. To better describe whats going on, after it slows down, it will boot to the login screen relatively quickly. After it hits the login screen, iff you look at the HD LED it will be glowing bright green for long duration. After you enter your credentials at the log in screen it will take between 10-15 minutes after you log in before you really get full control of the pc. It will go through stages of locking up because of the heavy IO Load and they HD LED will stay bright green the entire time. Something to note is that if you just reboot and leave the pc alone (never log in) for say 30 minutes and log in later then everything will be fine. I absolutely dread having to reboot in the middle of the day. I try to reboot before i leave every day so i don't have to deal with the 10-15 minute hit i get when i reboot.

I do install quite a bit of software because of what i do (developer). There are other developers in my group by i seem to run the most types of software. Their PCs seem to start up relatively fast. To address some things i know will come up:

1. Unfortunately our organization will not allow us to run SSDs so we are running spinning rust
2. Its not a DNS problem. I've had to deal with DNS problems before and this is not the problem here
3. I have a local profile and not a remote profile.
4. I'm of course loging in using AD

I've tried a variety of tools to figure out the problem but have not yet been able to figure out whats going on. I tried autoruns to see if there is anything that stood out as not being needed. I've tried run procmon during a reboot. I've tried to use disk portion of resource monitor.

Does anyone have any suggestions / tips to try to figure out whats causing this problem. I assume its something i have installed but figuring out what has been quite a challenge.