Are you running Microsoft Windows 98 or Microsoft Windows 98 Second Edition?
Many USB devices are not very well supported in either,
but Second Edition provided some bug fixes for USB device support.
(if you are not running Second Edition)
I recommend you upgrade to Microsoft Windows 98 Second Edition
http://www.amazon.com/s/ref=nb_ss_gw?url=search-alias%3Daps&field-keywords=Windows+98+second+edition&x=0&y=0
which has (marginally) better USB device support.
Really better USB device support came with Microsoft Windows ME & 2000.
If you have a (Dell, HP, IBM, ...) "brand" name computer,
then you might be able to get a "Microsoft Windows 98 Second Edition" product recovery, restore, or support compact disc or floppy diskettes from them for a nominal handling/shipping charge?
You did not mention which brand of USB flash drive?
Some USB flash drive vendors have drivers which you can download,
not sure that they would have a driver compatible with Microsoft Windows 98 & your specific USB flash drive?
For instance, Lexar's drivers
http://www.lexar.com/drivers/index.html
work with their products
WARNING: may or may not work with other brands, potentially corrupting or erasing your files!
Microsoft Windows 98 is no longer officially supported by Microsoft,
but you can try searching the Microsoft Windows 98 Support Center for various solutions:
http://support.microsoft.com/ph/1139
search for "USB" ...
Microsoft has a generic/sample USB Mass Storage Device driver for Windows 98
http://support.microsoft.com/kb/257751
which you can try, again it is NOT supported, and
not sure whether it will work with your USB flash drive?
You can try downloading third-party USB flash drive device drivers for Microsoft Windows 98, but most are unsupported, and some have dangerous bugs which could corrupt or erase your files.
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Alternatively,
to tranfer files from an (older) Microsoft Windows 98 system, you could either:
- copy or transfer them over a network connection
(again better supported in Second Edition, see above)
You would need to establish a network connection,
either via a dial-up modem, parallel port, or (Ethernet) network interface card
(again see the Microsoft Windows 98 support center above)
- use an older product like a Iomega Zip external parallel drive
http://www.amazon.com/s/ref=nb_ss_gw?url=search-alias%3Daps&field-keywords=iomega+zip+parallel&x=0&y=0
which are available (surplus or used) fairly inexpensively
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References or resources:
http://www.gudstoff.com/getting-your-usb-flash-drive-to-work-on-windows-98.htm
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For more information or assistance,
contact me LeheckaG on AskVille.