Save a current page and update its thumbnail

Press CTRL+S.

Save all modified pages/thumbnails in the same multi-page view

On the File menu, point to Save and then select All pages in this tab.

Update preview of current or all open pages

Use other options under File > Save.

Configure auto-save of pages

1.On the Edit menu, click Preferences.

2.On the Main tab, under Autosave, click Enabled

3.In Changes between saves, enter the number of changes after which the page is to be saved.