Yes, Firefox 40.0.3 runs on Windows XP SP2 and SP3.

I'm not sure why your question refers to Firefox 38, but there is an Extended Support Release of Firefox 38 that also runs on Windows XP SP2 and SP3.

Note that some Firefox features are missing on Windows XP, in particular, Firefox depends on the system for MPEG video decoding and Microsoft did not release those components for Windows XP.

Yes Windows XP sp2 is still the minimum Windows needed to run Firefox since Firefox 13.0 so yes WinXP SP3 will run the current Firefox 40.0.3 Release and 38.2.1 ESR.

The only real change with Windows requirements in last while is with Win64 Firefox as one will need 64-bit Windows 7 at minimum. The 64-bit Windows XP, Vista and servers cannot run Win64 Firefox since 36.0 or 37.0 (forget at moment) development builds. The first Release to have Win64 will be Firefox 42.0 if all goes well.

jscher2000 said

Yes, Firefox 40.0.3 runs on Windows XP SP2 and SP3. I'm not sure why your question refers to Firefox 38, but there is an Extended Support Release of Firefox 38 that also runs on Windows XP SP2 and SP3. Note that some Firefox features are missing on Windows XP, in particular, Firefox depends on the system for MPEG video decoding and Microsoft did not release those components for Windows XP.

I use the OOB OpenFileDialog or SaveFileDialog Firefox in Silverlight 34, But I upgraded Firefox to 40, 39. The use of OpenFileDialog will be suspended and the collapse of the browser。 Thank you

James said

Yes Windows XP sp2 is still the minimum Windows needed to run Firefox since Firefox 13.0 so yes WinXP SP3 will run the current Firefox 40.0.3 Release and 38.2.1 ESR. The only real change with Windows requirements in last while is with Win64 Firefox as one will need 64-bit Windows 7 at minimum. The 64-bit Windows XP, Vista and servers cannot run Win64 Firefox since 36.0 or 37.0 (forget at moment) development builds. The first Release to have Win64 will be Firefox 42.0 if all goes well.

I use the OpenFileDialog or SaveFileDialog in Silverlight OOB Firefox 34 , But I upgraded Firefox to 40, 39. The use of OpenFileDialog will be suspended and the collapse of the browser。

If you decide to switch to the Extended Support Release version of Firefox 38 (ESR), here is how I suggest installing it:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(A) Download a fresh installer for Firefox 38.2.1esr from https://www.mozilla.org/firefox/organizations/all/ to a convenient location. (Scroll down to your preferred language.)

(B) Exit out of Firefox (if applicable).

(C) Rename the program folder, either:

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\FxOld

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\FxOld

(D) Run the installer you downloaded in (A). It should automatically connect to your existing settings.

Note: Some plugins may exist only in that old folder. If something essential is missing, look in these folders:

• \FxOld\Plugins
• \FxOld\browser\plugins