'... nor can I find it anywhere on my computer!' - the type of search(es) used was / were not specified; thus, based on the assumption that the 'Utilities' folder exists; but, has been relocated:
01. Locate and click on the 'Spotlight' icon on the upper right side of the menu bar. It looks like a white magnifying glass in a blue circle.
02. Enter 'Utilities' (without the single quote marks). When the search is completed, a drop down sheet will appear.
03. Locate the 'Folders' section in the resultant drop down sheet, and look for 'Utilities'. If you see it (the 'Utilities' folder'), move the mouse cursor over it ('Utilities') and click once. The selected 'Utilities' window should then open. You should see such applications as 'Console', 'Disk Utility', etc.
Assuming that the above steps worked, you now want to place the 'Utilities' folder back into the 'Applications' folder - of your (boot) hard disk drive.
04. Press and keep pressed the 'Command' key (there is one on each side of the 'spacebar' key) as you click on the title ('Utilities') of the window. A drop down sheet will appear. Typically, 'Applications' would be the second name listed. Regardless of the second items' name drag the mouse down to it, and release the mouse button. A window will appear with 'Utilities' folder listed in it.
05. Move the resultant window to the left side of your screen.
06. Locate the upper right hard disk drive icon on the 'Desktop', and double click on it. You should note the 'Applications' folder in the window.
07. Move the window to the right, so as not to over lap with the left side window.
08. Carefully, click on (and keep the mouse button pressed) and drag the 'Utilities' folder (from left side window) onto the 'Applications' folder of the right side window, and release the mouse button.
Do not worry if the 'Applications' folder automatically opens - just release the mouse button, when the mouse cursor is over any area of the window - that is not a folder (you do not want to accidently move the 'Utilities' into a folder of the 'Applications' folder; but, into the 'Applications' folder itself).
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Naturally, you could use 'Spotlight' to also search for 'Disk Utility', of which one expects to be in the 'Utilities' folder. If so, apply the steps provided above.
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'How can I get it back?' - ...
If the above search suggestions failed to locate the 'Utilities' folder, and / or any application(s) of the 'Utilities' folder - then there is the possibility that the 'Utilities' folder was deleted. If so, you would have to preform an 'Archive and Install' of your MacOS X, and any or all related Apple updates.