Unity Pro 3.4 suddenly won't start

Unity Engine
1

My Unity has worked flawlessly until tonight.
Suddenly it won’t start at all. No clues as I only get the Wait-icon for about 10 seconds and then nothing more happens.
I have tried with Uninstall and Install again. So what to do next.

Unity version = latest 3.4
OS: Windows 7 64 bit SP1
Graphics card: GTX280
NVidia drivers: Latest

Probably this won’t help, but this is what Windows Event Viewer gives.

  • System
  • Provider

[ Name] Application Error

  • EventID 1000

[ Qualifiers] 0

Level 2

Task 100

Keywords 0x80000000000000

  • TimeCreated

[ SystemTime] 2011-08-26T22:51:32.000000000Z

EventRecordID 41132

Channel Application

Computer Roland-Dator

Security

  • EventData

Unity.exe
3.4.0.27242
4e295076
KERNELBASE.dll
6.1.7601.17651
4e211319
e06d7363
0000b9bc
100
01cc6442b117b0ee
C:\Program Files (x86)\Unity\Editor\Unity.exe
C:\Windows\syswow64\KERNELBASE.dll
f0cd892a-d035-11e0-80da-001d7dd4bb44

2

Fixed the problem.
Turned DEP off for Unity.exe

3

What’s DEP ?

4

Data Execution Prevention

Feature that protects the system from viruses and other security threats. The Windows constantly monitors the programs running on our system and closes them if they perform any malicious activity. But sometimes we want a certain program(s) to run even if the Windows alerts us that it is a malicious one.

Here is how to turn it off for a program
Change Data Execution Prevention settings