Old laptop with Bitcoin Folder

[bosshyip]

Hello everyone I found my old laptop and I turned it on and saw that there was a bitcoin folder all dated back from 2011 . And what I did next is to see if there an application on the laptop for bitcoin. I found it great!
but the thing is it prompted me to install a new bitcoin qt wallet software . I thought it would just open up but anyway Installed  it And it says zero balance.  Huh   Went back to check the wallet.dat file and the date has been changed to present day .
Does this mean I have overwritten it?
I did not save the wallet.dat file before installing the bitcoin core wallet again.
What must I do? Will system restore put the old back on file for that dated file?

It might have some  BTC in there . Any help will be greatly appreciated with BTCBTCBTC Thanks.