Firefox consistently crashes at startup

Question

Firefox is consistently crashing at startup even in safe mode. Only Firefox is giving me problems, Internet Explorer and other programs works fine.
One of these two things usually happen:
The first is that it will slow the computer to a crawl and then Werfault will close the program. This usually happens when I first try Firefox after booting. Under Event Viewer it generates the following two Application errors:
Event 1000 - Faulting application firefox.exe, version 11.0.0.4454, time stamp 0x4f5ecc44, faulting module MSVCR80.dll, version 8.0.50727.6195, time stamp 0x4dcddbf3, exception code 0xc0000006, fault offset 0x0003a7f7, process id 0x1674, application start time 0x01cd092f8d05a15e.
Event 1005 - Windows cannot access the file C:\Windows\winsxs\x86_microsoft.vc80.crt_1fc8b3b9a1e18e3b_8.0.50727.6195_none_d09154e044272b9a\msvcr80.dll for one of the following reasons: there is a problem with the network connection, the disk that the file is stored on, or the storage drivers installed on this computer; or the disk is missing. Windows closed the program Firefox because of this error.
Program: Firefox
File: C:\Windows\winsxs\x86_microsoft.vc80.crt_1fc8b3b9a1e18e3b_8.0.50727.6195_none_d09154e044272b9a\msvcr80.dll
Additional Data
Error value: C000009C
Disk type: 3
The second thing that consistently happens not long after the above is if I try Firefox it will instead generate the crash reporter and show this:
AdapterDeviceID: 03d0
AdapterVendorID: 10de
AvailableVirtualMemory: 1925783552
BuildID: 20120312181643
CrashTime: 1332533354
EMCheckCompatibility: true
FramePoisonBase: 00000000f0de0000
FramePoisonSize: 65536
InstallTime: 1332406199
Notes: AdapterVendorID: 10de, AdapterDeviceID: 03d0, AdapterSubsysID: 26011019, AdapterDriverVersion: 8.17.12.9610
ProductID: {ec8030f7-c20a-464f-9b0e-13a3a9e97384}
ProductName: Firefox
ReleaseChannel: release
SecondsSinceLastCrash: 46
StartupTime: 1332533335
SystemMemoryUsePercentage: 37
Theme: classic/1.0
Throttleable: 1
TotalVirtualMemory: 2147352576
URL:
Vendor: Mozilla
Version: 11.0
Winsock_LSP: MSAFD Tcpip [TCP/IP] : 2 : 1 :
MSAFD Tcpip [UDP/IP] : 2 : 2 : %SystemRoot%\system32\mswsock.dll
MSAFD Tcpip [RAW/IP] : 2 : 3 :
MSAFD Tcpip [TCP/IPv6] : 2 : 1 : %SystemRoot%\system32\mswsock.dll
MSAFD Tcpip [UDP/IPv6] : 2 : 2 :
MSAFD Tcpip [RAW/IPv6] : 2 : 3 : %SystemRoot%\system32\mswsock.dll
RSVP TCPv6 Service Provider : 2 : 1 :
RSVP TCP Service Provider : 2 : 1 : %SystemRoot%\system32\mswsock.dll
RSVP UDPv6 Service Provider : 2 : 2 :
RSVP UDP Service Provider : 2 : 2 : %SystemRoot%\system32\mswsock.dll
MSAFD NetBIOS [\Device\NetBT_Tcpip_{7225B89C-C910-42F1-A560-D0EFB0E774C1}] SEQPACKET 2 : 2 : 5 :
MSAFD NetBIOS [\Device\NetBT_Tcpip_{7225B89C-C910-42F1-A560-D0EFB0E774C1}] DATAGRAM 2 : 2 : 2 : %SystemRoot%\system32\mswsock.dll
MSAFD NetBIOS [\Device\NetBT_Tcpip6_{6C37D96C-24E1-44E9-84A0-EE7289C6B494}] SEQPACKET 1 : 2 : 5 :
MSAFD NetBIOS [\Device\NetBT_Tcpip6_{6C37D96C-24E1-44E9-84A0-EE7289C6B494}] DATAGRAM 1 : 2 : 2 : %SystemRoot%\system32\mswsock.dll
MSAFD NetBIOS [\Device\NetBT_Tcpip6_{B36F64DF-9B03-498F-847F-B44147E80314}] SEQPACKET 0 : 2 : 5 :
MSAFD NetBIOS [\Device\NetBT_Tcpip6_{B36F64DF-9B03-498F-847F-B44147E80314}] DATAGRAM 0 : 2 : 2 : %SystemRoot%\system32\mswsock.dll
MSAFD NetBIOS [\Device\NetBT_Tcpip6_{7225B89C-C910-42F1-A560-D0EFB0E774C1}] SEQPACKET 3 : 2 : 5 :
MSAFD NetBIOS [\Device\NetBT_Tcpip6_{7225B89C-C910-42F1-A560-D0EFB0E774C1}] DATAGRAM 3 : 2 : 2 : %SystemRoot%\system32\mswsock.dll
Oddly enough, if I screw with it long enough it may start to work and when it does it will start up and work fine from then on until I shut down my PC. Once it's boot up again, the consistent crashing returns.
I've searched Google and have tried everything to no avail. I've done clean installs of Firefox, system restore, chkdsk for both system files and bad blocks, registry cleaner, uninstalling all versions of Visual Runtime C++, full scan for malware/virus, etc. and nothing has worked. Help please.

Answer 1

That can be a problem with accessing the secmod.db file in the profile folder.
Rename secmod.db (secmod.db.old) in the Firefox Profile Folder in case there is a problem with the file.
You can use this button to go to the Firefox profile folder:
*Help > Troubleshooting Information > Profile Directory: Open Containing Folder
Create a new profile as a test to check if your current profile is causing the problems.
See "Basic Troubleshooting: Make a new profile":
*https://support.mozilla.org/kb/Basic+Troubleshooting#w_8-make-a-new-profile
If that new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files.
See:
*http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox