Can not access web site

Running Win98. Using IE 5.5 with 128 bit encription. Cannot access ibm.com or bankone.com on this computer, but can access any other. Can access them from any other computer in this office. Have gone to a command prompt and did a ping on www.bankone.com and the dns works. It returns the correct IP. IE will access the websites using the IP address, but all lower pages in the site require the www. address, not the IP address. This is the second time I’ve seen this situation in the past 12 months. On the first one, we renamed the Windows directory and reinstalled Windows 98. That worked, but does not tell me what is causing the problem. Anyone with any ideas?