Just purchased the quickbooks pro 2019. I've been using quickbooks premier 2009. I have multiple companies I run from quickbooks. For some reason I can't install both companies with the quickbooks pro 2019.
Let's examine this statement: "For some reason I can't install both companies with the quickbooks pro 2019."
Do you use Word or Excel? These are Programs. QB also is a Program. A Program is installed Once.
Then, you have Data files. The Word letters are data files. You launch Word to work with Word Letters. These are Word's Data file types.
QB Company files are .qbw files. You use the QB program to manage as many .qbw files are you want to. There is no Limit. The QB program opens one data file, and you use the program tools to manage that data file. Then, you close that data file and open a different company data file, still using the QB program, because these are QB data files.
The files from 2009 won't work directly with QB 2019; that is a 10-year jump. You will want to ask Intuit or someone to update the files in interim jumps, such as QB 2012-2015-2019 and Rebuild the files in between each jump. You waited a Long Time for this.