Actually, you do have ACR. Open Photoshop and then File > Open and select a RAW file. ACR will open and display your RAW image. Alternately, when in Bridge, double-click a RAW file and that will open PS and ACR.
John, I you don't state what platform your working on. Mac /PC are close.together. Ver 4 of LR is old. You are looking for Camera Raw installer for Adobe Photoshop CC and CS6
This the the one that might answer with your problem. Hopefully , this will work. Check to see if it has your camera profile in the installer. Good luck.
There is no program icon for camera raw. It is a plug-in that works with Photoshop, and it should have been installed automatically when Photoshop was installed. Camera raw will be activated when you try to open a raw file from Bridge or Photoshop (depending on how you have set your preferences). But you cannot just start camera raw as a program. It is a plug-in that depends on having a supporting application installed.
And in addition to JimHess' message, the same engine is used when you select the CameraRaw filter (from the Filter menu).