Windows 7: getting BSOD win7 64bit

Microsoft (R) Windows Debugger Version 6.11.0001.404 X86
Copyright (c) Microsoft Corporation. All rights reserved.


Loading Dump File [C:\Users\K\Desktop\Minidump\033011-41496-01.dmp]
Mini Kernel Dump File: Only registers and stack trace are available

Symbol search path is: SRV*C:\Symbols*http://msdl.microsoft.com/download/symbols;srv*e:\symbols
*http://msdl.microsoft.com/download/symbols
Executable search path is: 
Windows 7 Kernel Version 7601 (Service Pack 1) MP (8 procs) Free x64
Product: WinNt, suite: TerminalServer SingleUserTS
Built by: 7601.17514.amd64fre.win7sp1_rtm.101119-1850
Machine Name:
Kernel base = 0xfffff800`03067000 PsLoadedModuleList = 0xfffff800`032ace90
Debug session time: Wed Mar 30 16:38:22.783 2011 (GMT-4)
System Uptime: 0 days 7:10:33.814
Loading Kernel Symbols
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Loading User Symbols
Loading unloaded module list
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*                        Bugcheck Analysis                                    *
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Use !analyze -v to get detailed debugging information.

BugCheck 3B, {c0000005, fffff880057ad23f, fffff88013f36f40, 0}

Probably caused by : Dot4.sys ( Dot4!GetChannelFromHandle+f7 )

Followup: MachineOwner
---------

0: kd> !analyze -v
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*                        Bugcheck Analysis                                    *
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SYSTEM_SERVICE_EXCEPTION (3b)
An exception happened while executing a system service routine.
Arguments:
Arg1: 00000000c0000005, Exception code that caused the bugcheck
Arg2: fffff880057ad23f, Address of the exception record for the exception that caused the bugcheck
Arg3: fffff88013f36f40, Address of the context record for the exception that caused the bugcheck
Arg4: 0000000000000000, zero.

Debugging Details:
------------------


EXCEPTION_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%08lx referenced memory at 0x%08lx. The memory could not be %s.

FAULTING_IP: 
Dot4!GetChannelFromHandle+f7
fffff880`057ad23f 44384903        cmp     byte ptr [rcx+3],r9b

CONTEXT:  fffff88013f36f40 -- (.cxr 0xfffff88013f36f40)
rax=fffffa800a1aacc0 rbx=0000000000000000 rcx=0000000000000000
rdx=0000000000000002 rsi=0000000000000000 rdi=0000000000000003
rip=fffff880057ad23f rsp=fffff88013f37920 rbp=0000000000000000
 r8=fffff88013f379a0  r9=0000000000000000 r10=00000000003a201e
r11=0000000000000000 r12=fffff88013f37a18 r13=fffffa800acfde40
r14=fffffa800bc1e660 r15=fffffa8007a302f0
iopl=0         nv up ei ng nz na po nc
cs=0010  ss=0018  ds=002b  es=002b  fs=0053  gs=002b             efl=00010286
Dot4!GetChannelFromHandle+0xf7:
fffff880`057ad23f 44384903        cmp     byte ptr [rcx+3],r9b ds:002b:00000000`00000003=??
Resetting default scope

CUSTOMER_CRASH_COUNT:  1

DEFAULT_BUCKET_ID:  VISTA_DRIVER_FAULT

BUGCHECK_STR:  0x3B

PROCESS_NAME:  hpqtra08.exe

CURRENT_IRQL:  0

LAST_CONTROL_TRANSFER:  from 0000000000000000 to fffff880057ad23f

STACK_TEXT:  
fffff880`13f37920 00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : Dot4!GetChannelFromHandle+0xf7


FOLLOWUP_IP: 
Dot4!GetChannelFromHandle+f7
fffff880`057ad23f 44384903        cmp     byte ptr [rcx+3],r9b

SYMBOL_STACK_INDEX:  0

SYMBOL_NAME:  Dot4!GetChannelFromHandle+f7

FOLLOWUP_NAME:  MachineOwner

MODULE_NAME: Dot4

IMAGE_NAME:  Dot4.sys

DEBUG_FLR_IMAGE_TIMESTAMP:  4a5bca90

STACK_COMMAND:  .cxr 0xfffff88013f36f40 ; kb

FAILURE_BUCKET_ID:  X64_0x3B_Dot4!GetChannelFromHandle+f7

BUCKET_ID:  X64_0x3B_Dot4!GetChannelFromHandle+f7

Followup: MachineOwner
---------

0: kd> lmvm Dot4
start             end                 module name
fffff880`0579f000 fffff880`057c7000   Dot4       (pdb symbols)          c:\symbols\dot4.pdb\CB8143AB792B4362851A9E4965F49D381\dot4.pdb
    Loaded symbol image file: Dot4.sys
    Mapped memory image file: C:\Symbols\Dot4.sys\4A5BCA9028000\Dot4.sys
    Image path: \SystemRoot\system32\DRIVERS\Dot4.sys
    Image name: Dot4.sys
    Timestamp:        Mon Jul 13 20:00:16 2009 (4A5BCA90)
    CheckSum:         00029327
    ImageSize:        00028000
    File version:     6.1.7600.16385
    Product version:  6.1.7600.16385
    File flags:       0 (Mask 3F)
    File OS:          40004 NT Win32
    File type:        3.7 Driver
    File date:        00000000.00000000
    Translations:     0409.04b0
    CompanyName:      Microsoft Corporation
    ProductName:      Microsoft® Windows® Operating System
    InternalName:     dot4.sys
    OriginalFilename: dot4.sys
    ProductVersion:   6.1.7600.16385
    FileVersion:      6.1.7600.16385 (win7_rtm.090713-1255)
    FileDescription:  IEEE-1284.4-1999 Driver
    LegalCopyright:   © Microsoft Corporation. All rights reserved.