adobe reader 9.1 downloadingIf I want to download Adobe Reader 9.1, should I first remove the older Adobe reader?

Does a newer version automatically make the older version obsolete?
no you can just over write it

it'sadobe reader 9.1 downloading now 9.4
No. I updated last week & Adobe will automatically remove the old version first if removing itadobe reader 9.1 downloading is required.
just install the latest version, it will automatically remove the previous version.