Originally posted by stecal
From a checklist on installing Oracle on Windows:

Do you have at least 75MB of free disk space in C:\TEMP?
Oracle needs space in the TEMP directory as it installs. The Oracle Universal Installer (OUI) requires up to 75MB of space in the TEMP directory, as defined by the NT environment variables TMP or TEMP. Please note that moving the TEMP/TMP settings to another drive (non C:\) may not resolve this issue.

Similar problem:

You may obtain an I/O error on C:\TEMP when the Installer has reached the point of Oracle product install.
Solution Description
--------------------
Check the permisions on C:\TEMP.
1.- Go to Start/Program/Windows NT Explorer
2.- Put the mouse arrow on the directory C:\TEMP
3.- Choose the properties option
4.- Remove the check mark from Read_only
The space allocation of 75MB is not for the 8i version but for the 9i version when it is being upgraded from 8i to 9i within the same maching requires any such kind of pre allocation of memory?

Just a suggestion required.
your reply appreciated.

VAST