How you get them back depends on how you got rid of them.
1) Try opening the database while holding down the shift key. If this works,
go to Tools|Startup... and check the Allow Toolsbars/Menus boxes.
2) Open the database, press Ctrl+G to go to the immediate window. Type
RunCommand acCmdStartupProperties
and press enter, this will bring up the dialog in #1.
3) At the immediate window type
DoCmd.ShowToolbar "toolbar name", acToolbarWhereApprop
close and reopen Access. This will need to be done for each toolbar.
Here is a list of toolbar names:
Alignment and Sizing
Database
Menu Bar
There are more; however, once you have the menu bar you can go to
View|Toolbars|Customize and reset the rest of them from the Toolbars tab.