Generally, the ActiveX Controls are located in either the Windows or System32 folder.
What has happened in the past is after you install your runtime version is someone else installs Their program that uses a Different version of the same ActiveX, since several of these ActiveX use the same name for several different versions your program may develope errors.
With runtime its not real easy to figure out your program is not Referencing to the "wrong" ActiveX.
I put a copy of the ActiceX in my program file and reference to that one. That way the likelyhood of someone else replacing mine is remote.