Is there a way of restoring (or finding) the browser historys I accidentally deleted?
Woudl a system restore bring them back?
Yes,System Restore should work to recover browser history.
Or,you could try restoring what was deleted.If you have Spybot 2.4,then open Quarantine,and you should see a History section with dates beside them,so you can pick the right one.
If there are other things deleted accidentally,such as cookies that you wanted to keep,perhaps because your internet passwords are no longer remembered when you go to login to a place,then those things should be available in quarantine,too.
So,you'd check mark whatever you'd like to restore,then click the Restore Selected button.
You can tell Spybot to stop scanning for Tracks (https://www.safer-networking.org/faq/usage-tracks/) by opening Spybot-S&D Start Center,checkmark Advanced Mode,click Settings(saying yes if prompted by UAC,if applicable),then the categories tab,and somewhere in the Spybot window,rightclick and select Spyware scan only.