Acrobat version conflict when opening an electronic form

Question

I have created an electronic form using Acrobat 9.0 that takes advantage of users being able to open, edit and save the form using Reader 9.0. The form includes a version-checking javascript to ensure users minimally have Reader 8.0 or 9.0 installed so that they can properly modify & save.
Unfortunately, some users have Acrobat 7.0 Standard installed on their system, and despite the fact they have set Reader 9.0 as the default application to globally open files having the .pdf extension, they're running into a problem where they always get a "wrong version" error message involving Acrobat 7.0 when trying to open the form, even from within Reader. The only remedy we've found so far is to remove the Acrobat 7.0 Standard program from their system.
Of course, this is not satisfactory, since they need to be able to modify their own and other files using their Acrobat 7.0 Standard, and do not wish to upgrade to a newer version at this time.
We'd sure appreciate any assistance or solutions with this dilemma.
Thanks in Advance,
--Calamity Vic--

Answer 1

Hello Michael,
Thanks for your helpful response. I was not aware of any limitation for users to prevent an installation of both Acrobat and Reader on the same system. Many of us have both in order that we can use Acrobat to develop our documents, then use the free Reader program to test and verify their function as our users will experience them.
FYI, the javascript in the form is set up to check if the user has Reader 8 or better and close the doc if not. The reason for this is that users of the form need to be able to fill the form plus add personal stamps and such -- then save their changes -- which function was only implemented at version 8.
Here is the javascript used:
if (app.viewerVersion < 8) {
    app.alert("You must have Acrobat Reader 8.0 or better to use this form.\n\nYou can find more information about and download the latest version FREE by going to http://www.adobe.com/products/reader/")
    this.closeDoc(true)
I see one solution to this that our "super user" who uses both Acrobat 7 and needs to open the form in Reader could consider setting up a second system which has Acrobat 7 installed, with Reader only installed on their main system. This is probably not very feasible though, since there will likely be a group (as many as 5-10) of super users here needing to use our form in this way.
Please let me know your opinion.
Many thanks again,
--Calamity Vic--