Norton should never delete a file that does not actually contain a virus. No original Windows files, from any legal installation disks have ever, to my knowledge, been reported as infected.

If a critical file is infected and deleted, you should be able to do an "overlay" reinstallation of Windows and/or of Internet Explorer without the necessity of a reformat. In older Win versions this often will return everything to "default" setup; but in newer versions it usually will keep most settings. Especially in the obsolete Win95/Win98/WinME, an overlay may return you to the default IE, which I believe was ver 4.0 for the Win versions affected. IE4.0 lacks security levels and encryption required by some websites so you might need a reinstall of a current IE.

If Windows is not repairable by doing a repair, or an overlay installation, it would normally mean that the virus with which you were infected has done some nasty stuff. Neither Norton nor Windows can be blamed for that, unless you can provide assurance that your Norton was always kept current and was always run in real-time protection mode(s).

Even if critical functions are disabled on your machine, with any remotely recent Win version you should be able to boot to Safe Mode from your installation disk(s) and use the necessary functions from there to make repairs without a reformat. You may also have followed the instructions at original installation to make a "recovery disk" that would allow a Safe Mode boot and would provide necessary management tools - - but I don't know where mine is either. (I would expect to use the install CD if the need ever came up.)

Your Norton log(s) should show what specific file(s) were deleted, and with a boot to Safe Mode and with your installation disk(s) you can extract and replace any individual file that was deleted, although a complete system overlay installation usually is recommended if there's major corruption.

Lots of sympathy extended; but I'm afraid without more specific information, not much credibility here.

Situations of the kind you describe most often occur when AV updates are neglected, a virus/worm gets onboard and is allowed to do substantial damage. In worst case, the virus may reformat your HD for you. When you update the AV, all it can do is delete the original virus, which may require deleting a necessary file in rare cases. The AV cannot track all the peripheral damage the virus may have done while it lurked and waited for you to update and find it. Not an accusation, of course. Just quoting the odds.

John