If you fancy some spidery web theme to your PC then check out the following 2 themes for Windows.
Wintry Webs theme
“Webs sheathed in a thin veneer of frost appear as if encrusted in tiny diamonds. This free theme for Windows harkens the arrival of winter. “
Webs & Waterdrops theme
“Nature appears bedecked in gossamer strands of tiny crystal droplets in this free Windows theme.”