How do I Open two company files in Quickbooks accountant's edition?

1. Open first company file 
2. Go back to the NovelAspect cloud page 
3. Start QuickBooks PAE again get get another instance and open the second company file. 
4. If step 3 fails, go back to the first company file and Uncheck the "Keep QuickBooks running for quick startup" option under Edit-Preferences.
5. Log off from the NovelAspect cloud and try starting with step 1 again.

http://support.quickbooks.intuit.com/support/pages/inproducthelp/Core/QB2K12/ContentPackage/Verticals/Accountant/qbae_multi_instance.html

In the NovelAspect environment, the database files are located on servers without Quickbooks application.  Double clicking the company files will generate an error in method 1 mentioned in the article.