XP and Vista are no longer supported by the release version of Firefox. You will need to use the Firefox Extended Support Release version which was originally made for organizations who needed an up to date Firefox with security fixes and no major updates or changes. You can download it at https://www.mozilla.org/en-US/firefox/organizations/

• https://www.mozilla.org/en-US/firefox/organizations/faq/

For your crashing isssue, can you get a list of crash report IDs?

The crash report is several pages of data. We need the report numbers to see the whole report.

1. Enter about:crashes in the Firefox address bar and press Enter. A Submitted Crash Reports list will appear, similar to the one shown below.
2. Copy the 5 most recent Report IDs that start with bp- and then go back to your forum question and paste those IDs into the "Post a Reply" box.

Note: If a recent Report ID does not start with bp- click on it to submit the report.

(Please don't take a screenshot of your crashes, just copy and paste the IDs. The below image is just an example of what your Firefox screen should look like.)

Also, your Firefox provided this self-identification information (user agent string):

Mozilla/5.0 (Windows NT 4.10; rv:52.0) Gecko/20100101 Firefox/52.0

Windows XP should identify as Windows NT 5.1 so your Firefox may be set to run in a backwards compatible mode -- meaning that Windows hides certain new and changed functions from Firefox so it thinks you're running an earlier version. Since XP is the earliest compatible version, you should turn that off. Here's how:

• Right-click the Firefox desktop shortcut and choose Properties
• Click the Compatibility tab. For best results, make sure no checkboxes are checked here. (Example Windows 7 screenshot attached.)

Another reason for a strange user agent string is if some add-on or external software has overridden the normal identification. You can check the setting in this article to see whether it has that odd information: How to reset the default user agent on Firefox.