3rd attempt same thing after not being able to work from my computer for a day. So 1 days lost wages and it was now Monday. Microsoft still wasn't answering so I opted for the 10 hour wait with DR DOS help line. After 10 hours I started to explain the issue. I didn't even finish my sentence. I said, "I'm trying to install Windows 4.0 and..." then I was interrupted. He said, "Yes we know what the problem is. Boot off your DR DOS floppy and go to your DR DOS directory. Type rename DRDOS.CFG to DRDOS.BAK. Install windows 4.0. It will finish in about 10 hours. After you are done rename DRDOS.BAK back to DRDOS.CFG. You'll be good to go". I was like, "WTF!!!!". He said, "Yes. Windows considers DRDOS a threat to their monopoly of the operating system. So they check before completing the install to see whether this file exists. If it does they won't let you complete the install."
DR DOS received countless calls and it literally swamped their help lines and cost them millions. As a startup this was something they could ill afford. Eventually this and other blatantly unfair trade practices by Microsoft put them under. They filed suit. In the early 80's trying to get a jury of 12 to understand what an operating system even is was an impossible task. But they succeeded.... 10 years later after they had already filed for bankruptcy. Microsoft was found in violation of antitrust and the former stock holders were awarded a pittance in damages. Microsoft remains one of the dominant OS to this day. I will NEVER forgive them for wasting my time and costing me (one of their customers) valuable time and money dealing with their crap. So we agree there are abuses. But these aren't capitalism. We have antitrust laws in place for just this reason. Unfortunately, our legal system is very slow in dealing with this crap and legal fees are outrageous. Lawyers can drag on a case far beyond the point were damages can be fully redressed.
When I finally got to speak to Microsoft to file a complaint and at least vent my anger at SOMEONE from Microsoft they gave me the standard response. "DR DOS is not compatible with WINDOWS 4.0 so we were doing a service to our customers preventing installation of both products to avoid the customer losing data". I continued to run DR DOS for quite some time thereafter and NEVER had any issues. Evidence later came out this was a complete fabrication.