I try to fix the problem with opening the original Windows iso and search for dbgeng.dll(x86) As i search i found two: • DBGENG.DLL ( F:\AMD64 ) i gues this is the x64 - ( v5.2.3790.3959 ) - 1.56mb • WDBGENG.DL_ ( F:\I386 ) i gues this is the x86 - ( v5.2.3790.3959 ) - 1.01mb (expanded from the iso) I change the wdbgeng to dbgeng and place it in SYSWOW64 - and the DBGENG goes in SYSTEM32. I regsvr32 /s dbgeng.dll, and use cmd -> drwtsn32 -- no problems and here are some proof: The error stops, but when i open the application still closes, this time without error.... Application exception occurred: App: D:\Servers\csdm\hlds.exe (pid=5756) When: 29.4.2014 г. @ 08:09:02.531 Exception number: c0000005 (access violation) *----> System Information <----* Computer Name: IMB4 User Name: Xakep Terminal Session Id: 0 Number of Processors: 2 Processor Type: EM64T Family 6 Model 23 Stepping 10 Windows Version: 5.2 Current Build: 3790 Service Pack: 2 Current Type: Multiprocessor Free Registered Organization: WXP Registered Owner: Xakep