mac book pro 17" 2009 boot issue

[jestermonty]

Hi,

I installed new AntiVirus software on my mac and now when I try to start all I get in a flashing Apple logo, behind a flashing No Entry logo behind a flashing ? Symbol.

I've put a link to a YouTube video showing it below.

http://m.youtube.com/watch?v=HCMn5m1hFIk

Have tried all the reboot procedures to no avail.

 

[simsaladimbamba]

Which AV software did you install?

Have you tried all of these steps?

Mac doesn't boot

Resolve startup issues and perform disk maintenance with Disk Utility and fsck

Troubleshooting: My computer won't turn on

A flashing question mark appears when you start your Mac​

Currently there are zero viruses affecting Mac OS X in public circulation, but there are other kinds of malware existing, that can infect your Mac.
To learn more about malware in Mac OS X and what steps can be taken to protect yourself, read the following F.A.Q.:

Mac Virus/Malware Info by GGJstudios​

 

[jestermonty]

Hi, I've repaired the hard drive using first aid but no cannot eject my install disc to check if normal start up.works? Thanks for your help.

 

[simsaladimbamba]

Hi, I've repaired the hard drive using first aid but no cannot eject my install disc to check if normal start up.works? Thanks for your help.

Force Eject a Stuck CD or DVD
Apple Computers: Troubleshooting the slot load optical disc drive​

 

[jestermonty]

Nearly there

So I've now re-installed my operating software and not lost any data which is great but the mac keeps crashing, in particular when I either try to perform a Time Machine back up or when I load Mail. I am using the machine standard apple mail client.

Any suggestions as to what to try?