When our household bought a Vista laptop, I migrated our install of Quicken 2002 to the new computer. My wife and I have separte accounts, and we update the checkbook separately. When she went to balance the checkbook, she noticed that my entries were missing.
On further investigation, it turns out that when I run Quicken, I can see my entries, but not hers. When she runs Quicken, she sees her entries, but not mine. It appeared that we are using two different databases. Quicken 2002 is supposed to write its files to the c:\Program Files\QUICKENW directory. I had given each of our non-Admin users access rights to write to that directory. I installed [Process Explorer](http://download.sysinternals.com/Files/ProcessExplorer.zip) so that I could see what files Quicken had open, and their location. It turns out that Quicken was writing its files to C:\Users\\[USERNAME]\AppData\Local\VirtualStore\Program Files\QUICKENW\. Why was it doing that? What is this VirtualStore thing?
Apparently, Windows Vista enforces security policy and doesn’t allow applications to write to C:\Program Files. Instead, it redirects badly behaved applications, like Quicken 2002, to write files to a per-user [VirtualStore](http://www.google.com/search?q=vista+virtualstore) directory, and it does this silently (for backwards compatibility). I wish Vista had simply denied write access to Quicken, so I would have known that there was a problem early on, before getting into this mess of having two diverging checkbook databases. I like the additional security that Vista enforces, but it’s inconvenient in subtle and exasperating ways.
Now I need to figure out how to merge our separate copies of the checkbook.
Update: I never did merge the two quicken databases.