How to find people's e-mails on Yahoo?

Cant find my emails on the yahoo server?

• I have installed windows 7 from an earlier Vista operating system but after backing up my computer particularly my outlook email I cant find 16000 emails that I have amassed. Can I set my yahoo email server to an earlier date to retrieve my emails which contain files I do not want to lose.

• Answer:

  NEW YAHOO! MAIL IS STILL UNSTABLE....IT WOULD BE BEST TO GO BACK TO YOUR PREVIOUS VERSION OF YAHOO! MAIL... To go back to YAHOO! MAIL CLASSIC... Turn off Javascript - you'll then be asked if you want to return to Mail Classic, click "yes". If you don't know how to turn off Javascript... For SAFARI: Open SETTINGS>click PREFERENCES>>click SECURITY>>Uncheck ENABLE JAVA and ENABLE JAVASCRIPT IMPORTANT:Remember to RE-ENABLE JAVA and JAVASCRIPTING back ON when you are back in Mail Classic because without it some mail functions won't work. For IE: Open TOOLS > INTERNET OPTIONS >> SECURITY. In security click "CUSTOM LEVEL" -> disable active scripting in the scripting section. IMPORTANT:Remember to turn JAVASCRIPTING back ON when you are back in Mail Classic because without it some mail functions won't work. For FIREFOX: Open TOOLS -> OPTIONS -> CONTENT, click on "DISABLE JAVASCRIPT". Now hit F5 to refresh the page while you are in Yahoo! email in order to switch back... In the options, click (PERMANENT) to switch back to YAHOO! Classic. DO NOT click the "ONE TIME ONLY" option. IMPORTANT: Turn JAVASCRIPT back ON once you have your "CLASSIC" account back. PLEASE ACKNOWLEDGE IF THIS SOLUTION WORKS BY CLICKING BEST ANSWER..THANKS