leave well (enough) alone

leave well (enough) alone

To refrain from changing, disturbing, or becoming involved in something so as to avoid unintentionally causing (or worsening) problems. To be honest, you're better off leaving well alone at this point. She's so angry that anything you say will just make things worse. Messing with the registry can cause catastrophic problems for your computer. If it isn't already totally busted, I would leave well enough alone.
See also: alone, leave, well
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

leave well enough alone

Also, let well enough alone. Do not try to change something lest you make it worse. For example, This recipe has turned out fine in the past, so leave well enough alone. The idea behind this expression dates from ancient Greek times, specifically Aesop's fable about a fox who refused a hedgehog's offer to take out its ticks lest, by removing those that are full, other hungry ones will replace them. Put as let well alone from the early 1700s, it was first recorded as let well enough alone in 1827. Also see let sleeping dogs lie.
See also: alone, enough, leave, well
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

leave well alone

If you leave well alone, you do not interfere in something, because it is all right as it is and you might make it worse. He knew when to leave well alone and when to interfere. Gordon knows his business, he says, and I should just leave well alone.
See also: alone, leave, well
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012

leave well alone

refrain from interfering in or changing something, for fear of making it worse.
See also: alone, leave, well
Farlex Partner Idioms Dictionary © Farlex 2017

leave/let well enough alone

Do not try to improve matters lest you make them worse. This idea was stated in ancient Greek times. In Aesop’s fable, the fox refused the hedgehog’s offer to remove its ticks, “lest by removing these, which are full, other hungry ones will come.” There is a medieval French version of the saying, Assez est bone, lessez ester (It is good enough, let it be). An English proverb for many centuries, the phrase became the motto of Sir Robert Walpole, prime minister from 1715 to 1717 and again from 1721 to 1742. A slangy twentieth-century Americanism meaning the same thing is if it ain’t broke don’t fix it. Reporting on a meeting between West German Chancellor Helmut Kohl and President George H.W. Bush concerning the future of NATO in view of German unification, Strobe Talbott wrote, “They both believe in the old adage, ‘If it ain’t broke, don’t fix it.’ NATO has kept the peace for 40 years, and there’s no reason to believe it can’t do so for another 40” (Time, July 2, 1990). See also let sleeping dogs lie.
See also: alone, enough, leave, let, well
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer
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