I have just had a heck of a time with installing BPA (Architect) Evaluation on a Windows Server 2003 machine. There were no inherent issues with the product itself, but some gotchas that I thought I might point out. For the following, I assumed you are installing on a single machine for testing/evaluation purposes like I was.
For one, if you were familiar with BPA 10.1.3.3, there is no longer an auto-installable olite database option. You must use Oracle XE Universal (or better) and you should have it installed locally prior to installing BPA. Note: You should use XE Universal specifically so you get the AL32UTF8 character set that is expected by the BPA install.
After I got the character set squared away, I continued to receive a database connection error