I have decided to restart the whole process. Please answer the following questions to help guide me.
1.Do you have instructions on how I can install vision?
2.If I decide to use the production, how far back can I go since I took a snapshot after installing Oracle Ebusiness R12. Can I go back to that point and start from there? if yes, how do I do that?
3.Could the problem be from before Oracle was installed or after the installation?
4.Since the issue is that of connecting to oracle from windows, how far back do you think I should go to correct this problem?

Sorry Matopra for the late reply. Due to some circumstance we could not attend the forums.

Before you restart the installation verify if all services are up and runnning fine (with status 0). If they are then the problem is not in the installation. you need to look into fixing the problem at your Windows. (Make sure linux firewall is off).

You need to go as far back as reinstalling Linux. If you have done wrong setup to Linux then it will come biting you again. Wrong host domain settings is the common problem.

Also the problem could be in your stage. If your checksum is not coming out 100% ok then you need to redownload the files as well

The installation for Vision would exactly be the same as the installation for Fresh/Prod. However you will need more space. Simply select Vision option at the Rapidwiz.

It is not a good idea to learn Oracle at Vision as it comes preconfigured up to an extent and you miss learning that preconfigured part. I do not support Vision related issued in the forum.