Nothing leaps out at me from the crash reports, unfortunately.

Could you try starting Firefox in its Safe Mode? In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

Hold down the Shift key when starting Firefox.

A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

Also, why Firefox 40? Version 40 is not secure; Mozilla discloses security flaws after each new release.

If Firefox in its Safe Mode does not help,

Start your Computer in safe mode with networking. Then start Firefox. Try Safe websites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

Some of your crash reports weren’t sent to the Mozilla Servers.

In the address bar, type about:crashes<enter>. Note: If any reports do not have BP in front of the numbers/letters, click it to submit them.

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

starting mozilla in safe mode doesn't help me........ starting computer in safe mode also i tried but no use

1e1f938d-a859-4d29-80ee-7f7aa77b6db5 6e17a606-c0bf-4720-a2e4-9654a5057c72 39f4296f-5234-41fc-b252-9752ef1f13f1 200e4ab4-76d5-46a9-9841-19afc3195dad

these are my crash report

It was asked before why are you usinmg an unsafe and unsupported Firefox 40 ? Upgrading to the Current release may help it will now be Fx50.

• Update Firefox to the latest release

Have you got crash reports that were generated and then submitted from your crashes in Firefox's safe mode. The Crash IDs you list do not have the prefix bp- and do not appear to have been submitted and processed.

Some of your crash reports weren’t sent to the Mozilla Servers.

In the address bar, type about:crashes<enter>. Note: If any reports do not have BP in front of the numbers/letters, click it to submit them.

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

bp-434ca7cb-2b5b-4831-b2b0-739ef2161130 bp-c0c03adc-b87c-4635-9668-9d7572161130 bp-109a3aff-ce69-4d5c-a46c-157592161130 bp-efcaff94-f589-44f8-88c1-80f522161130 bp-fb4f3395-c432-4b9c-b25c-bfd222161130 bp-385ca173-3e91-42c3-bb7b-428b12161201

all the files that download from mozilla are corrupted..... the files are fully downloaded, but when run those files it say "the file is corrupted".... not able to install the crome also (online installer) via firefox.

Product Firefox Release Channel release Version 40.0.3 Build ID 20150826023504 OS Windows 7 OS Version 6.1.7600

bp-434ca7cb-2b5b-4831-b2b0-739ef2161130

Signature: mozilla::dom::PageTransitionEventBinding::GetProtoObjectHandle

No programs were flagged. +++++++++++++++++++++++++++++++++++++++++++++++++ bp-c0c03adc-b87c-4635-9668-9d7572161130

Signature: js::GCMarker::processMarkStackTop

Attention Sumo's there are 10 related bug reports

No programs were flagged. ++++++++++++++++++++++++++++++++++++++++++++++++ Product Firefox Release Channel release Version 43.0.1 Build ID 20151216175450 OS Windows 7 OS Version 6.1.7600

bp-109a3aff-ce69-4d5c-a46c-157592161130

Signature: mozilla::AsyncEventDispatcher::AsyncEventDispatcher

icudt55.dll = International Components for Unicode +++++++++++++++++++++++++++++++++++++++++++++++++ Product Firefox Release Channel release Version 43.0.1 Build ID 20151216175450 OS Windows 7 OS Version 6.1.7600

bp-efcaff94-f589-44f8-88c1-80f522161130

Signature: mozilla::AsyncEventDispatcher::AsyncEventDispatcher

No programs were flagged. +++++++++++++++++++++++++++++++++++++++++++ bp-fb4f3395-c432-4b9c-b25c-bfd222161130

Signature: mozilla::AsyncEventDispatcher::AsyncEventDispatcher

No programs were flagged

Start your Computer in safe mode with networking. Then start Firefox. Try Safe websites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

Using Windows Internet Explorer, Download Firefox For All languages And Systems {web link} and save the file.

Hi again. I did not notice any of the Crash IDs as relating to Firefox's safe mode or using the current Fx50.0.2 or even the rrcent Fx49. It may help to have such crash IDs.

Additionally Fred is asking you to try testing in Windows safemode.