Installing Oracle Issues ____oracle

Recent Oracle upgrades, from Oracle8 to Oracle9i, have encountered a lot of trouble.
The first is the uninstall problem. Because Oracle8 did not use the normal uninstall method, the installation of the oracle9i is difficult. The correct uninstall steps are as follows:
1. Closure of all Oracle services and procedures;
2. Select Start | Program |oracle Installation Products command, run Universal Installer, pop-up Welcome dialog box;
3. Single Machine uninstall product button, pop-up Inventory dialog box;
4. Select all nodes in the Inventroy dialog box, click Delete, confirm;
5. Select Start | run input regedit and press ENTER, select Hkey_local_machine/software/oracle, delete this image, and then select hkey_local_machine/system/ Currentcontrolset/services, scroll through this list to remove all Oracle-related options;
6. Remove all Oracle groups and icons from the desktop, startup, and program menus;
7. Reboot the system;
8. Delete the installation directory, including files. All Oracle uninstall is complete.
Second install Oracle also encountered a hint: in the installer Exchange area C:/Documents and settings/....../local settings/temp not enough disk space, please ensure that at least 110K disk space, my C disk still has 9G space, How could there be no room? The final solution is to change the TEMP directory settings in the Windows environment variable, c:/documents and settings/....../local settings/temp to C:/temp, and then the installation goes well.