Can I run two versions of the same product together
Whether you can run two versions of Microsoft Money together depends on the two versions of Money that you want to run.
If you want to run, say Money 2002 and Money 2005 together, then you need to install the 2002 version (the earlier one) first and then the 2005 version (the later version) in another directory. If you download, say OFX statements from your financial institutions, then these will go into the 2005 (later) product (unless you save the file and then manually import it into Money 2002).
If you have two versions that are from the same year, for example, Microsoft Money 2005 Standard and Microsoft Money 2005 Premium, then you cannot run these at the same time unless you use software such as Virtual PC. The reaoson is that they share the same registry keys and would interfere with each other.
In addition, you cannot run two versions of Money at the same time (even if they are from different years). If you do, you'll get a 'Money is already running' error (seen also with Article 312
It is possible to install two different country versions on the same machine, subject to them not being the same 'year' version. Again, you can't run these concurrently.