Problem with qt creater and linker

My platform is windows 7
I use last qt creator (2.5.0)
My issue is :

Code:

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:-1: error: LNK1181: cannot open input file 'C:\libarchive\lib.obj'

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My .pro is

Code:

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#-------------------------------------------------
#
# Project created by QtCreator 2012-07-04T22:10:36
#
#-------------------------------------------------
 
QT       -= core
 
QT       -= gui
 
TARGET = libarchive
CONFIG   += console
CONFIG   -= app_bundle
 
LIBS += C:\libarchive\lib
 
LIBS += -larchive_static
 
INCLUDEPATH += C:\libarchive\include
 
TEMPLATE = app
 
 
SOURCES += main.cpp

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When move lib in project directory and comment LIBS += C:\libarchive\lib it's work
What i'm doing wrong ??

Lines 15 through 17:

Code:

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LIBS += -LC:/libarchive/lib -larchive_static

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Note the "-L". Also note the use of forward slashes; not essential, but it suppresses a warning about un-escaped backslashes.