First of - do restart. Alt+F4->Restart - exactly like that, no shutdown or hibenate.
There something wrong with addresses in RAM (not exist or no right to read-write). This can caused by game corruption, system or hardware. No guaranteed solution.
Try DEP solution from here:
[url=http://www.pcgamingwiki.com/wiki/Blood_Omen:_Legacy_of_Kain]http://www.pcgamingwiki.com/wiki/Blood_Omen:_Legacy_of_Kain[/url]
(manually add exe files for gaming tools and games or any program where DEP cause problems, there is solution to entirely disable it by CMD command, but entilery disabling is no recommended)
Check memory and system by two tools mentioned here:
http://answers.microsoft.com/en-us/windows/forum/all/explorerexe-error-the-instruction-0x00000000/90fcabb4-f947-4331-9836-e900d65e48fa if you on Windows 8 or higher - check for latest
stable updates\-builds. They are mandatory on that OS's (at same time bring a lot of troubles and fix them later). But before install DirectX (June 2010) and DirectX web-installers -> then go to Windows Control - Programs - Enable\disable Windows features - Legacy - Legacy DirectPlay.
Than check for updates, install
and restart to apply directx changes.
Completely reinstall video driver(s). Try to add game exe manually to video driver Control panel and choose integrated or discrete GPU.
Set maximum power performance in Windows and video drivers.
if you use 3rd party antivirus disable it temporary.
Reinstall game to X:\Games\*Kain-1*\ (somethign without spaces, "_" non-latin letters and special symbols, short - and not in program files and better not to system drive at all)
Anyway set game exe admin run. This temporary partially disable Windows Defender for that exe and all further, but Defender can keep looking at game folder (and 100% keep look at Program Files).
Did you use GOG Galaxy to install game or offline installer? Same rules to Galaxy +something more. For offline version just reinstall, while for any online distribution reinstalling do nothing. Validate. Twice. After every downlaoding.