Blue Screen, No Internet And Bit Defender Not Responding

I have recently upgraded from BD 2010 to Internet security 2012 i downloaded the new software and it asked me to uninstall the previous version first once this had finished it asked me to restart my PC then i got the Blue screen of death saying "fatal error and my pc is shutting down to prevent further damage" and it kept doig this on a loop.

I have windows 7 on a sony notebook.

I spoke to someone on the web chat and they told me to start with safe mode with networking then google chrome would not work then the rest of my internet would not connect.

I was then told downlaod a support tool log this did not work

then a sysdump this also would not work

then i run the 'autoruns.exe' file and this worked and this is what i was sent

"that you have another security solution installed on yoursystem, which could conflict with BitDefender"

I have used bit defender for the last 2 years and before that i had a norton trial that come with the PC new i had to uninstall this norton trail to install bitdefender 2010 so i do not have any other security running.

I started my PC by starting with last know good configuration as this was the only way to get it back on then i downloaded removal tools for norton and bitdefender and run them just to be sure that nothing was left on there. Then i downloaded internet security 2012 again and it stopped my google chrome working again but i could get internet explorer to work. I turned it off thinking i had fixed the main problem but the next time i tried to turn my PC on i got blue screen of death again and i have to keep restarting to last know good configuration to get my PC to work.

Bit defender is still on my PC but when i try to open it it comes up with an error message saying bitdefender is not working.

Not sure what else i can do????