Bests & Worsts Reviews from Amazon

I am a long time user of both Quicken and QuickBooks (since the mid 90's). I run both applications on the same PC (currently a Pentium 4 2.0 GHz with 512 MB of memory). Through the years I have upgraded both applications each year as the new versions come out. This time I upgraded my Quicken 2004 Premier Home & Business to the 2005 version accepting all the defaults of the installation program. Quicken 2005 opened and worked fine after the install. However, QuickBooks Basic 2004 would not open anymore, giving error codes and transmitting reports to Intuit. Attempting to find assistance on Intuit's web site yielded no results, phone support is only on a pay per call basis and email to the company support site via their web site did not provide any response. Quicken is an OK product but any product that breaks another during installation, especially a sister product, and one as financially vital as QuickBooks is to a business and then have the company fail to provide any support is totally unacceptable.