Many thanks for your reply.  The error is

LINK : fatal error LNK1104: cannot open file 'boost_zlib-vc90-mt-gd-1_41.lib'

Below is a transcript that shows i) the error, ii) that the file exists, iii) and that it is rebuilt if deleted.

I will be very happy to provide any further information you like, and most grateful for any help.

KH

=============================================

Try running bjam ...

$ bjam
...patience...
...found 749 targets...
...updating 9 targets...
msvc.link.dll d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\zlib\msvc-9.0e
xpress\debug\threading-multi\boost_zlib-vc90-mt-gd-1_41.dll
   Creating library d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\zlib\msv
c-9.0express\debug\threading-multi\boost_zlib-vc90-mt-gd-1_41.lib and object d:\
tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\zlib\msvc-9.0express\debug\thre
ading-multi\boost_zlib-vc90-mt-gd-1_41.exp
msvc.manifest.dll d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\zlib\msvc-
9.0express\debug\threading-multi\boost_zlib-vc90-mt-gd-1_41.dll
msvc.link.dll d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\msvc-9.0expres
s\debug\threading-multi\boost_iostreams-vc90-mt-gd-1_41.dll
   Creating library d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\msvc-9.0
express\debug\threading-multi\boost_iostreams-vc90-mt-gd-1_41.lib and object d:\
tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\msvc-9.0express\debug\threading
-multi\boost_iostreams-vc90-mt-gd-1_41.exp
msvc.manifest.dll d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\msvc-9.0ex
press\debug\threading-multi\boost_iostreams-vc90-mt-gd-1_41.dll
msvc.link.dll bin\msvc-9.0express\debug\threading-multi\l.dll
LINK : fatal error LNK1104: cannot open file 'boost_zlib-vc90-mt-gd-1_41.lib'

        call "D:\Program Files\Microsoft Visual Studio 9.0\VC\vcvarsall.bat" x86
 >nul
link /NOLOGO /INCREMENTAL:NO /DLL /DEBUG /MACHINE:X86 /subsystem:console /out:"b
in\msvc-9.0express\debug\threading-multi\l.dll" /IMPLIB:"bin\msvc-9.0express\deb
ug\threading-multi\l.lib"    @"bin\msvc-9.0express\debug\threading-multi\l.dll.r
sp"
        if %ERRORLEVEL% NEQ 0 EXIT %ERRORLEVEL%

...failed msvc.link.dll bin\msvc-9.0express\debug\threading-multi\l.dll bin\msvc
-9.0express\debug\threading-multi\l.lib bin\msvc-9.0express\debug\threading-mult
i\l.pdb bin\msvc-9.0express\debug\threading-multi\l.pdb...
...skipped <pbin\msvc-9.0express\debug\threading-multi>blah.exe for lack of <pbi
n\msvc-9.0express\debug\threading-multi>l.lib...
...skipped <pbin\msvc-9.0express\debug\threading-multi>blah.pdb for lack of <pbi
n\msvc-9.0express\debug\threading-multi>l.lib...
...failed updating 3 targets...
...skipped 2 targets...
...updated 4 targets...

=================================================
Check the file exists ...

Administrator@BLAH /cygdrive/d/tean/dt
$ find /cygdrive/d/tean/t1/boost_1_41_0/bin.v2 -name boost_zlib-vc90-mt-gd-1_41
.lib
/cygdrive/d/tean/t1/boost_1_41_0/bin.v2/libs/iostreams/build/zlib/msvc-9.0expres
s/debug/threading-multi/boost_zlib-vc90-mt-gd-1_41.lib

=================================================
Now delete it, run bjam again, note it is recreated but bjam cannot find it after it
has compiled it ...

$ rm /cygdrive/d/tean/t1/boost_1_41_0/bin.v2/libs/iostreams/build/zlib/msvc-9.0
express/debug/threading-multi/boost_zlib-vc90-mt-gd-1_41.*

Administrator@BLAH /cygdrive/d/tean/dt
$ bjam
...patience...
...found 749 targets...
...updating 11 targets...
msvc.link.dll d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\zlib\msvc-9.0e
xpress\debug\threading-multi\boost_zlib-vc90-mt-gd-1_41.dll
   Creating library d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\zlib\msv
c-9.0express\debug\threading-multi\boost_zlib-vc90-mt-gd-1_41.lib and object d:\
tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\zlib\msvc-9.0express\debug\thre
ading-multi\boost_zlib-vc90-mt-gd-1_41.exp
msvc.manifest.dll d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\zlib\msvc-
9.0express\debug\threading-multi\boost_zlib-vc90-mt-gd-1_41.dll
msvc.link.dll d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\msvc-9.0expres
s\debug\threading-multi\boost_iostreams-vc90-mt-gd-1_41.dll
   Creating library d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\msvc-9.0
express\debug\threading-multi\boost_iostreams-vc90-mt-gd-1_41.lib and object d:\
tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\msvc-9.0express\debug\threading
-multi\boost_iostreams-vc90-mt-gd-1_41.exp
msvc.manifest.dll d:\tean\t1\boost_1_41_0\bin.v2\libs\iostreams\build\msvc-9.0ex
press\debug\threading-multi\boost_iostreams-vc90-mt-gd-1_41.dll
msvc.link.dll bin\msvc-9.0express\debug\threading-multi\l.dll
LINK : fatal error LNK1104: cannot open file 'boost_zlib-vc90-mt-gd-1_41.lib'

        call "D:\Program Files\Microsoft Visual Studio 9.0\VC\vcvarsall.bat" x86
 >nul
link /NOLOGO /INCREMENTAL:NO /DLL /DEBUG /MACHINE:X86 /subsystem:console /out:"b
in\msvc-9.0express\debug\threading-multi\l.dll" /IMPLIB:"bin\msvc-9.0express\deb
ug\threading-multi\l.lib"    @"bin\msvc-9.0express\debug\threading-multi\l.dll.r
sp"
        if %ERRORLEVEL% NEQ 0 EXIT %ERRORLEVEL%

...failed msvc.link.dll bin\msvc-9.0express\debug\threading-multi\l.dll bin\msvc
-9.0express\debug\threading-multi\l.lib bin\msvc-9.0express\debug\threading-mult
i\l.pdb bin\msvc-9.0express\debug\threading-multi\l.pdb...
...skipped <pbin\msvc-9.0express\debug\threading-multi>blah.exe for lack of <pbi
n\msvc-9.0express\debug\threading-multi>l.lib...
...skipped <pbin\msvc-9.0express\debug\threading-multi>blah.pdb for lack of <pbi
n\msvc-9.0express\debug\threading-multi>l.lib...
...failed updating 3 targets...
...skipped 2 targets...
...updated 6 targets...

Administrator@BLAH /cygdrive/d/tean/dt
$ find /cygdrive/d/tean/t1/boost_1_41_0/bin.v2 -name boost_zlib-vc90-mt-gd-1_41
.lib
/cygdrive/d/tean/t1/boost_1_41_0/bin.v2/libs/iostreams/build/zlib/msvc-9.0expres
s/debug/threading-multi/boost_zlib-vc90-mt-gd-1_41.lib