Save Time With Advanced Search
You can really save some time by using the Advanced Search options if you are searching for specific publications, authors, legal or want to restrict the date.
To access the options, click on the arrow (pull down menu) of the search box.
You'll get options to restrict results to specific authors, publications, dates and more.
More About Google Scholar
A Note on Browser Settings
Technically, your web browser remembers your preference settings in a "cookie" on your computer's disk, and sends this cookie to Goole Scholar along with every search.
Check that your browser isn't configured to discard Google Scholar cookies. Also, check if disabling various proxies or overly helpful privacy settings does the trick. Either way, your preferences are stored on your computer, not on Google's servers.
Google Scholar searches across many scholarly disciplines and sources: articles, theses, books, abstracts and court opinions, academic publishers, professional societies, online repositories, and universities with non scholarly results filtered out.