Here you go.

1. Copy contents of 8.1.? CD to local HD.
2. Once copied, modify oraparam.ini file to read as follows (substitute the absolute path for your CD: drive) where D: is the local CD drive.

[Oracle]
DISTRIBUTION=TRUE
SOURCE=D:/stage/products.jar
LICENSE_LOCATION=
JRE_LOCATION=D:/stage/Components/oracle.swd.jre/1.1.7.30/1/DataFiles/Expanded/jre
OUI_LOCATION=D:/stage/Components/oracle.swd.oui/1.7.1.9.0/1/DataFiles/Expanded
JRE_MEMORY_OPTIONS=-nojit -mx96m
DEFAULT_HOME_LOCATION=\oracle\ora81
DEFAULT_HOME_NAME=OraHome81
NO_BROWSE=
HLP_LOCATION=
EWT_LOCATION=
NLS_ENABLED=TRUE
BOOTSTRAP=FALSE

[IMAGES]
FILE1=images/o8i_1.gif
FILE2=images/o8i_2.gif
FILE3=images/o8i_3.gif
FILE4=images/o8i_4.gif
FILE5=images/o8i_5.gif
FILE6=images/o8i_6.gif
FILE7=images/o8i_7.gif
FILE8=images/o8i_8.gif

3. Run setup.exe from C:\temp\install\win32\setup.exe with the CD still in the CD drive.


For more information see bug 1518935 on Metalink.