The install files are located as below
$windows.~bt\Sources\Panther
Log location before Setup can access the drive.
$windows.~bt\Sources\Rollback
Log location when Setup rolls back in the event of a fatal error.
%WINDIR%\Panther
Log location of Setup actions after disk configuration.
%WINDIR%\Inf\Setupapi*.log
Used to log Plug and Play device installations.
%WINDIR%\Memory.dmp
Location of memory dump from bug checks.
%WINDIR%\Minidump\*.dmp
Location of log minidumps from bug checks.
%WINDIR%\System32\Sysprep\Panther
Location of Sysprep logs.
There from Technet for Windows 7
This may also help
Windows Vista setup log file locations
http://support.microsoft.com/kb/927521
Can you see any files in the new partition from Windows XP after you tried to install Windows 7?