Read perlop, especially the Quote and Quote like Operators section. You do not need double quotes here, as there is nothing to interpolate, so you can switch to single quotes:

my $string = 'sysBootFileWrite "QSDvxWorks.aif"';
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For cases where interpolation is needed, you can backslash the inner double quotes or use the qq operator:

print "He said, \"Hello, $darling.\"";
print qq(He said, "Hello, $darling.");
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