I installed ubuntu 12.4 ran great, tried to upgrade to 13 using the upgrade menu in ubuntu. I lost 12 and without system. I have repeatedly tried every link to get back 12.4.
I used wubi using no luck. I tried standard with 7zip,infan, and winrar, no luck. I realize this is an easy solve for a expenciened user. I am new but sold on the system.
Please help, i would like to learn how to install from standard download, i probably am not opening the file correctly. Please help in installing the system, would be great if it could be a step by step

Thanks for this Forum and any help,