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instruction at 0x00ac1aa4 memory cannot be read

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I have a computer in my shop that has firefox that will not start at all, not even in Safe mode. In normal mode of Windows 8.1 Firefox will not start at all. Going into Winows Safe Mode with networking is a little more revealing. I get the error Instruction at 0x00ac1aa4 referenced memory at 0x00000000 the memory could not be read. What is causing this error?

I have a computer in my shop that has firefox that will not start at all, not even in Safe mode. In normal mode of Windows 8.1 Firefox will not start at all. Going into Winows Safe Mode with networking is a little more revealing. I get the error Instruction at 0x00ac1aa4 referenced memory at 0x00000000 the memory could not be read. What is causing this error?

All Replies (3)

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Make sure that you have the latest updates for your security software and all major system drivers (graphics display, mouse, etc.).


Do a malware check with several malware scanning programs on the Windows computer. Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure that you update each program to get the latest version of their databases before doing a scan.

You can also do a check for a rootkit infection with TDSSKiller.

See also:

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Problem was fixed by a FireFox reinstall