BSOD tcpip.sys? at boot only

Hi everyone, Hi dear Jerome, I go BSOD (or a simply "total OS hang" > power off) at boot **ONLY**, therefore I have to leave the pc always turned on (with zero problems) since 3 weeks. But I prefer the old behaviour, i.e. shutdown during every night ;) hardware and software are always the same here, since...a lot years. Memory: the long test told me all is ok: I stopped it after the 12th (!) pass with zero errors: impressive! It seems nothing to do with antivirus/firewall, even if I was "sure" that the cause were CIS. I add here: 1) full memory dump (text bottom) 2) event viewer logs http://www99.zippyshare.com/v/PbLPkBX9/file.html http://www71.zippyshare.com/v/tDnIb10U/file.html What to do to be able to reboot the pc wothout BSOD? and, even important too, why BSOD happens at boot only? Thanks in advance for suggestions. Best, IRQL_NOT_LESS_OR_EQUAL (a) An attempt was made to access a pageable (or completely invalid) address at an interrupt request level (IRQL) that is too high. This is usually caused by drivers using improper addresses. If a kernel debugger is available get the stack backtrace. Arguments: Arg1: 00000001, memory referenced Arg2: 00000002, IRQL Arg3: 00000001, bitfield : bit 0 : value 0 = read operation, 1 = write operation bit 3 : value 0 = not an execute operation, 1 = execute operation (only on chips which support this level of status) Arg4: 826c0b39, address which referenced memory Debugging Details: ------------------ WORKER_ROUTINE: +0 00000001 ?? ??? WORK_ITEM: 826c0b39 CURRENT_IRQL: 2 DEFAULT_BUCKET_ID: VISTA_DRIVER_FAULT BUGCHECK_STR: 0xA PROCESS_NAME: System TAG_NOT_DEFINED_c000000f: FFFFFFFF8B934000 TRAP_FRAME: 8b933eac – (.trap 0xffffffff8b933eac) ErrCode = 00000002 eax=00000001 ebx=00000012 ecx=8b933f2c edx=8acd91e1 esi=8acd91e0 edi=8acd91e4 eip=826c0b39 esp=8b933f20 ebp=8b933f38 iopl=0 nv up ei ng nz na pe nc cs=0008 ss=0010 ds=0023 es=0023 fs=0030 gs=0000 efl=00010286 nt!KeAcquireQueuedSpinLockAtDpcLevel+0x19: 826c0b39 8908 mov dword ptr [eax],ecx ds:0023:00000001=???????? Resetting default scope LAST_CONTROL_TRANSFER: from 826c0b39 to 82667e9d STACK_TEXT: 8b933eac 826c0b39 badb0d00 8acd91e1 826c5508 nt!KiTrap0E+0x1c5 8b933f1c 8ac719ca 00000480 865dade0 3ecc8c00 nt!KeAcquireQueuedSpinLockAtDpcLevel+0x19 8b933f38 8ac7302f 865dade0 00000000 00000000 tcpip!RtlAcquireReadLockAtDpcLevel+0x38 8b933f50 8ac72181 00000002 8b914120 8b933fe0 tcpip!TcpUpdateIsnGenerator+0x13 8b933f88 826c4662 865dade0 00000002 519fd639 tcpip!TcpPeriodicTimeoutHandler+0x25b 8b933ff4 826c2295 8b9cfcc8 00000000 00000000 nt!KiRetireDpcList+0x147 8b933ff8 8b9cfcc8 00000000 00000000 00000000 nt!KiDispatchInterrupt+0x45 WARNING: Frame IP not in any known module. Following frames may be wrong. 826c2295 00000000 0000001b 00c7850f bb830000 0x8b9cfcc8 STACK_COMMAND: kb FOLLOWUP_IP: tcpip!RtlAcquireReadLockAtDpcLevel+38 8ac719ca 33c0 xor eax,eax SYMBOL_STACK_INDEX: 2 SYMBOL_NAME: tcpip!RtlAcquireReadLockAtDpcLevel+38 FOLLOWUP_NAME: MachineOwner MODULE_NAME: tcpip IMAGE_NAME: tcpip.sys DEBUG_FLR_IMAGE_TIMESTAMP: 533f4cca FAILURE_BUCKET_ID: 0xA_tcpip!RtlAcquireReadLockAtDpcLevel+38 BUCKET_ID: 0xA_tcpip!RtlAcquireReadLockAtDpcLevel+38 Followup: MachineOwner