Personally I've never been keen on using Firefox as my default browser since I've always used the Mozilla suite from way back, before which I was using the Netscape Communicator suite). Yes, this is a concern right now for some legacy systems that are otherwise running fine on Win-XP Pro SP3. i consider it would concern any single core cpu. (ms has stopped delivering updates to windows 7 SSE cpu computers since juli or august). and windows 7 cant update any longer without SSE2, there is EOL of such systems right now. That's great to know that FF-ESR 45.90 is more secure than the regular FF 49.0X.īrummelchen wrote:there exist NO current firefox build for XP, neither with´or with or without SSE2. In the meantime, I've also acquired the latest ESR 60.X version for other systems, though normally I am a Seamonkey user and am only using Firefox as a back up browser. So in this case, it was necessary to select the latest available non-SSE2 required ESR version, which was indeed ESR 45.9, which is what I've got installed now. Only ESRs will comply with that configuration switch value. Yes, the SSE2 compatibility issue was the constraint at hand hence the pre-version-49.0 requirement, but since then I've also discovered that ESRs also allows unverified plug ins / extensions to be installed without being blocked, despite the fact that in the regular Firefox consumer releases, it ignores the ABOUT:CONFIG parameters that disables the plug in signatures requirements. The ESR versions were based on 10.0, 17.0, 24.0, 31.0, 38.0, 45.0, 52.0 and now 60.0 The only reason why you could not use Firefox 49.0 or later versions on Windows is because the CPU you have does not support SSE2. James wrote:There was no ESR based on 48.0.

Mozilla firefox old version