This looks very similar to my problem - posted 16 Jan in this discussion group
(Installation of SQL Server 2005 Express Edition x86 fails to complete) and
still not resolved. In my system, the last signs of activity is found in a
(big) log-file named SQLSetup0004_<computername>_SQL.

The finals loggings below hints at some kind of problem with
"ASP temp directory" and "RS" feature - whatever the latter is ...

Could you check your log-file and see if you have the same problem !?

MSI (s) (D8:E0) [23:52:24:625]: Invoking remote custom action. DLL:
C:\WINDOWS\Installer\MSI1B2.tmp, Entrypoint: CheckIIS
Action start 23:52:24: CheckIIS.D20239D7_E87C_40C9_9837_E70B8D4882C2.
<Func Name='LaunchFunction'>
Function=CheckIIS
<Func Name='SetCAContext'>
<EndFunc Name='SetCAContext' Return='T' GetLastError='203'>
Doing Action: CheckIIS
PerfTime Start: CheckIIS : Mon Jan 16 23:52:24 2006
<Func Name='CheckIIS'>
MSI (s) (D8!74) [23:52:24:656]: PROPERTY CHANGE: Adding IISCHECKED property.
Its value is '0'.
<Func Name='WebFindBase'>
, 80, , 0
IIsWebInfo
IIsFilters
IIsWebServer
MSI (s) (D8!74) [23:52:24:765]: PROPERTY CHANGE: Adding SqlIISInstalled
property. Its value is '1'.
MSI (s) (D8!74) [23:52:24:765]: PROPERTY CHANGE: Adding SqlDefaultWebSite
property. Its value is '/W3SVC/1'.
MSI (s) (D8!74) [23:52:24:796]: PROPERTY CHANGE: Adding SqlASPNETInstalled
property. Its value is '1'.
<EndFunc Name='WebFindBase' Return='0' GetLastError='-2146893811'>
Skipping RS Feature Dependency Check
<Func Name='GetXMLAttributeValue'>
Error to find XML node /configuration/system.web/compilation
<EndFunc Name='GetXMLAttributeValue' Return='2' GetLastError='0'>
Failed to get ModuleID_RS_Server when getting the ASP Temp directory.