By following links from other sources as well as this one, I was able to locate the cleanup file, downloaded it and carefully selected only Adobe Reader to be removed. I had v. 6 (came with the computer) plus versions 8 and two versions of 9 installed,,,a total of over 300 megs that absolutely would not be removed using the normal methods. And each time I responded to an upgrade offer from Adobe, I thought the upgrade process was removing older versions. Not so! Trying to get help from Adobe was brain damage and required money.
The above program is no longer supported or offered by MicroSoft, but can be had elsewhere on the web. I checked it for malware and viruses before running the install.exe. It removed the offending software with no apparent residual problems. I downloaded Foxit PDF reader and couldn't be happier with the result. And I no longer have the "sharing conflict" issues which started this search in the first place.
I used AVG Free antivirus for a number of years and recently learned of Avira from a computer tech. I removed AVG and have been using Avira (smaller footprint) for about a year. The Windows Install Cleanup program found residual files from AVG and I cleaned those out too.
Hope this helps others with similar problems with Adobe Acrobat Reader issues.