是否可以并行运行多个Access实例？

I have multiple sets of code I need to run in Access 2007 and I have been trying to see if it would be acceptable to run them at the same time. Each set of data I need to have my Access VBA code run through takes about 5-8 hours to run. Would running them two at a time or all at once cause any problems? I have multiple sets of code I need to run in A