This might be a (very) long shot, but last weekend I spent hours trying to find out why my sound card drivers wouldn't work. It also gave me some vague error about NDIS.VXD (or similar name). As it turned out I had installed all Windows Updates available right after formatting and installing Windows 98 and one of the installed updates was known to cause this problem. After reformatting and not installing updates everything worked like a charm.
The moral of this story: in safe mode very little drivers are loaded. Perhaps you have a similar problem and is something you don't expect interfering with your connection: if it isn't loaded (safe mode) it won't cause a problem, if it is (no safe mode) it will cause a problem. Long shot, but it might help. Good luck
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