Is the modem driver an XP version, or the one you were using when it was Win 98?
If so, check your installation disk for the correct version and reinstall or see if the manufacturers has posted a new driver for XP on its website.
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This fantastic short film is packed with hidden TV and film references
Best external graphics cards (eGPUs) for Mac
Test : les écouteurs Bluetooth Soundcore Spirit X d’Anker