What is your computer system and Firefox?

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. Is the problem still there?

While still in Safe Mode,

Type about:support in the address bar and press Enter. Under the main banner, press the button; Copy Text To Clipboard.. Then in the reply box at the bottom of this page, do a right click in the box and select Paste. This will show us your system details. No Personal Information Is Collected.

If I try to hold down the shift key and start firefox it will not open at all.

Now having tried that I cannot get Firefox to open at all whether I hold the shift key down or do not hold it down.

I will download the update again to make it work and then go to about:support in order to answer your second question.

Application Basics

Name: Firefox Version: 44.0 Build ID: 20160123151951 Update Channel: release User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:44.0) Gecko/20100101 Firefox/44.0 Multiprocess Windows: 0/1 (default: false) Safe Mode: false

Crash Reports for the Last 3 Days

All Crash Reports

Extensions

Name: Adobe Acrobat - Create PDF Version: 1.2 Enabled: false ID: web2pdfextension@web2pdf.adobedotcom

Name: Adobe Contribute Toolbar Version: 6.0 Enabled: false ID: {01A8CA0A-4C96-465b-A49B-65C46FAD54F9}

Name: Skype Version: 8.0.0.9103 Enabled: false ID: {82AF8DCA-6DE9-405D-BD5E-43525BDAD38A}

Graphics

Adapter Description: NVIDIA GeForce GTX 660 Ti Adapter Drivers: nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um Adapter RAM: 2048 Asynchronous Pan/Zoom: none ClearType Parameters: D [ Gamma: 2200 Pixel Structure: R ClearType Level: 0 Enhanced Contrast: 300 ] D [ Gamma: 2200 Pixel Structure: R ClearType Level: 50 Enhanced Contrast: 400 ] Device ID: 0x1183 Direct2D Enabled: true DirectWrite Enabled: true (6.2.9200.17568) Driver Date: 2-5-2015 Driver Version: 9.18.13.4752 GPU #2 Active: false GPU Accelerated Windows: 1/1 Direct3D 11 (OMTC) Subsys ID: 36603842 Supports Hardware H264 Decoding: Yes Vendor ID: 0x10de WebGL Renderer: Google Inc. -- ANGLE (NVIDIA GeForce GTX 660 Ti Direct3D11 vs_5_0 ps_5_0) windowLayerManagerRemote: true AzureCanvasBackend: direct2d 1.1 AzureContentBackend: direct2d 1.1 AzureFallbackCanvasBackend: cairo AzureSkiaAccelerated: 0

Important Modified Preferences

browser.cache.disk.capacity: 358400 browser.cache.disk.filesystem_reported: 1 browser.cache.disk.smart_size.first_run: false browser.cache.disk.smart_size.use_old_max: false browser.cache.frecency_experiment: 2 browser.download.importedFromSqlite: true browser.places.smartBookmarksVersion: 7 browser.sessionstore.upgradeBackup.latestBuildID: 20160123151951 browser.startup.homepage_override.buildID: 20160123151951 browser.startup.homepage_override.mstone: 44.0 dom.apps.reset-permissions: true dom.mozApps.used: true extensions.lastAppVersion: 44.0 gfx.crash-guard.d3d11layers.appVersion: 44.0 gfx.crash-guard.d3d11layers.deviceID: 0x1183 gfx.crash-guard.d3d11layers.driverVersion: 9.18.13.4752 gfx.crash-guard.d3d11layers.feature-d2d: true gfx.crash-guard.d3d11layers.feature-d3d11: true gfx.crash-guard.glcontext.gfx.driver-init.direct3d11-angle: true gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle: true gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-d3d11: false gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-warp: false gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-try-d3d11: true gfx.crash-guard.status.d3d11layers: 2 gfx.crash-guard.status.d3d9video: 2 gfx.crash-guard.status.glcontext: 2 gfx.direct3d.last_used_feature_level_idx: 0 media.gmp-eme-adobe.abi: x86-msvc-x64 media.gmp-eme-adobe.lastUpdate: 1454006946 media.gmp-eme-adobe.version: 15 media.gmp-gmpopenh264.abi: x86-msvc-x64 media.gmp-gmpopenh264.lastUpdate: 1454006947 media.gmp-gmpopenh264.version: 1.5.3 media.gmp-manager.buildID: 20160123151951 media.gmp-manager.lastCheck: 1454345437 media.hardware-video-decoding.failed: false network.cookie.prefsMigrated: true network.predictor.cleaned-up: true places.database.lastMaintenance: 1454010169 places.history.expiration.transient_current_max_pages: 104858 plugin.disable_full_page_plugin_for_types: application/pdf plugin.importedState: true print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_bgcolor: false print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_bgimages: false print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_duplex: -437918235 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_edge_bottom: 0 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_edge_left: 0 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_edge_right: 0 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_edge_top: 0 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_evenpages: true print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_footercenter: print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_footerleft: &PT print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_footerright: &D print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_headercenter: print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_headerleft: &T print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_headerright: &U print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_in_color: true print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_margin_bottom: 0.5 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_margin_left: 0.5 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_margin_right: 0.5 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_margin_top: 0.5 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_oddpages: true print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_orientation: 0 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_page_delay: 50 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_paper_data: 1 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_paper_height: 11.00 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_paper_name: print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_paper_size_type: 0 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_paper_size_unit: 0 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_paper_width: 8.50 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_resolution: -437918235 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_reversed: false print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_scaling: 1.00 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_shrink_to_fit: true print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_to_file: false print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_unwriteable_margin_bottom: 0 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_unwriteable_margin_left: 0 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_unwriteable_margin_right: 0 print.printer_HP_LaserJet_M1522nf_MFP_UPD_PCL_6.print_unwriteable_margin_top: 0 privacy.sanitize.migrateClearSavedPwdsOnExit: true storage.vacuum.last.index: 1 storage.vacuum.last.places.sqlite: 1454010165

Important Locked Preferences

JavaScript

Incremental GC: true

Accessibility

Activated: false Prevent Accessibility: 0

Library Versions

NSPR Expected minimum version: 4.11 Version in use: 4.11

NSS Expected minimum version: 3.21 Basic ECC Version in use: 3.21 Basic ECC

NSSSMIME Expected minimum version: 3.21 Basic ECC Version in use: 3.21 Basic ECC

NSSSSL Expected minimum version: 3.21 Basic ECC Version in use: 3.21 Basic ECC

NSSUTIL Expected minimum version: 3.21 Version in use: 3.21

Experimental Features

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

Starting The Computer In Safe Mode;
Free Online Encyclopedia

The problem seems to have gone away as I was able to open firefox and it appears to be working correctly at this time.

Fingers crossed.