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A Windows .INF file can possibly be safely deleted, but a LOT more information would be needed to know what the impact would be. If it is affecting performance at all, there are two generally likely reasons.
First, if it's a "normal" .INF file, it's a setup file for some program. Deleting it might cause the program to run in a default mode. Or it might have no effect at all if the setup was only for the installation.
But second, if it's not a "normal" .INF file, we have no way to know what its purpose is. We don't know what would happen from deletion.
For a "normal" .INF file, a performance problem could arise from some setting in the file. The proper action would usually be to edit the file to change the setting. Deleting the file would make little sense in such a case.
Without knowing what the "call" was all about, the first thought was that it was a scam.