I am also not cisco professional
. Try this command for erase configuration and make IOS without any configuration.
On every message, after you type command press "NO":
erase startup-config
After this you must configure your router from beginning.
You can also try upgrade new IOS but you must download IOS files from Cisco site if you have valid cisco account.
Upgrade procedure find with google search because I dont know how that works.
Sorry about my bad English.