Windows boot drives using MBR can only boot from drives 2tb or less. The limit is with MBR not Windows. If you were booting from a GPT partition you can boot from drives over 2tb.
About half way down there is a list of compatible operating systems that can boot from GPT.
http://en.wikipedia.org/wiki/GUID_Partition_Table
When you initialize the disk, initialize using a GPT Partiton scheme and make sure that you have your chipset driver installed/updated.
I have a 4tb external drive here. I'll give it a test to make sure that I have everything right.
*Update- It defaults to initializing anything over 2tb as GPT. I formatted the drive as NTFS and mounted the drive. Worked just fine for me.