The solution proposed by jhollywd really works! Thank you. Thank you. Thank you. This was a really irritating glitch.
The instructions provided by jhollywd (but with additional detail) are as follows:
1) Add HP Deskjet 990c printer on LPT1 - Go to "Start", then "Devices and Printers" then Add a printer. Click on "Add a local printer" and select to use existing port LPT1. Click Next. Select HP in the left column. Select the HP Deskjet 990c. If you don't see it at first, continue to scroll down. Hp "Deskjet" printers are further down. Ignore the "HP Printers" listed at the beginning.
2) Name the new printer "Quicken HP Deskjet 990c" or whatever else you want to in order to identify it as the one you will use in quicken.
3) Once added, right click the new printer and open "Printer Properties". This is not the same as "Properties". Choose "Printer Properties".
4) Click on the "Ports" Tab. Change the printer port checkbox to that of the HP printer you actually want to print on. Scroll down if you don't see it at first.
5) Open Quicken and set your Quicken printer preference to the "QUicken HP 990c" and voila you will be able to print.
Note that the new Quicken Printer that you set up will not be visable in the printers list after you close the Devices and Printers window, but Quicken will continue to print to the actual HP printer.
Again, thanks go out to jhollywd.
As anyone who has followed this knows, I've tried everything including adding the 990C. And it never worked because HP Deskjet 990C never showed up as an option on the list of HP printers.
If this has happened to you simply run a Windows Update which is on the bottom right hand side of the page where you need to select the printer model #.
After completing the update then follow the directions provided by JGrayCPA1 and it's a breeze.
Two final observations:
1: When the 990C is initially installed it will try to print a "test page". The printer will freeze just like it's been doing in Quicken. Just ignore that.
2: The 990C installed as my default printer and my actual printer (HP 6210) has been replaced by the 990C (the 6210 no longer appears in my list of devices). It doesn't really matter since all of my printing preferences remain the same and I can print in every program.
Many thanks to all who contributed to the 990C fix.