Windows 7: Windows7 64bit: Computer freezes / no Bluescreen

Do you have a System Restore point before the problem started?

Look in Event Viewer for any errors at the time of the freeze, for a clue about whats causing the freeze.

If things are OK in safe mode, in the search box enter msconfig.exe and click on it. In the Startup tab disable everything except your antivirus app. Next in the Services tab click on Hide Microsoft Services and disable the remaining services. Restart and wait for the PC to freeze. If it is still running OK, go back to msconfig.exe and enable about half the the entries you disabled earlier. Reboot and see what happens. The idea is to find the startup program or service that is causing the problem by adding back the entries until you can find the offender.

Protokollname: Application
Quelle: Microsoft-Windows-LoadPerf
Datum: 18.09.2012 11:40:36
Ereignis-ID: 3002
Aufgabenkategorie:Keine
Ebene: Fehler
Schlüsselwörter:
Benutzer: SYSTEM
Computer: ***
Beschreibung:
Der Textzeichenfolgenwert zur Beschreibung des Leistungsindikators in der Registrierung ist falsch formatiert. Die falsch formatierte Zeichenfolge ist "". Das erste DWORD im Datenbereich enthält den Indexwert für die falsch formatierte Zeichenfolge, während das zweite und dritte DWORD im Datenbereich die letzten gültigen Indexwerte enthalten.
Ereignis-XML:
<Event xmlns='http://schemas.microsoft.com/win/2004/08/events/event'><System><Provider Name='Microsoft-Windows-LoadPerf' Guid='{122EE297-BB47-41AE-B265-1CA8D1886D40}'/><EventID>3002</EventID><Version>0</Version><Level>2</Level><Task>0</Task><Opcode>0</Opcode><Keywords>0x8000000000000000</Keywords><TimeCreated SystemTime='2012-09-18T09:40:36.672800000Z'/><EventRecordID>76373</EventRecordID><Correlation/><Execution ProcessID='3008' ThreadID='1604'/><Channel>Application</Channel><Computer>Tompo</Computer><Security UserID='S-1-5-18'/></System><UserData><EventXML xmlns:auto-ns2='http://schemas.microsoft.com/win/2004/08/events' xmlns='LoadPerf'><param1></param1><binaryDataSize>16</binaryDataSize><binaryData>00000000B1330000B1330000980B0000</binaryData></EventXML></UserData></Event>

Errors in the event viewer are not necessarily something to worry about. What you are looking for in event viewer is an error at or shortly before the freeze. It can be hard to decipher what the errors really mean. I don't speak/read German, it looks like Karl does, he should be back before long.

The idea of disabling half the startup and services is to speed up finding which group has the problem. After you find the half with the problem, you will start disabling each entry one at a time. Reboot after each change.

It would not hurt to run sfc to see if there are any corrupt system files. Type CMD in the search box and right click on cmd.exe and select Run As Administrator. At the command prompt enter sfc /scannow (notice the space after the c). It will look for and try to repair corrupt system files.