Blue Screen of Doom upon installing Avast...

Avast Free Antivirus / Premium Security
1

… the highly rated free anti-virus program. I downloaded it at CNET. As it was downloading, my PC went bluescreen, with the following message:

Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7601.2.1.0.768.3
Locale ID: 1033

Additional information about the problem:
BCCode: 50
BCP1: FFFFF961001DDE28
BCP2: 0000000000000000
BCP3: FFFFFA80078F11D6
BCP4: 0000000000000005
OS Version: 6_1_7601
Service Pack: 1_0
Product: 768_1

Files that help describe the problem:
C:\Windows\Minidump\030514-19780-01.dmp
C:\Users\Steven\AppData\Local\Temp\WER-80449-0.sysdata.xml

Read our privacy statement online:
http://go.microsoft.com/fwlink/?linkid=104288&clcid=0x0409

If the online privacy statement is not available, please read our privacy statement offline:
C:\Windows\system32\en-US\erofflps.txt

Thanks for any help interpreting this. I just want to make sure nothing serious happened, also would appreciate suggestions on next steps, if any, I should take.

2

have you removed your previous used AV before installing avast?

General: Uninstalling a third-party antivirus software http://www.avast.com/en-eu/faq.php?article=AVKB11#artTitle