I have a Dimension 2400 with Windows XP Home that I upgraded to SP2.  After the upgrade I began to have problems with my internet connection so I tried to use the "Repair" option, however, when doing so I got a pop-up informing me that "Windows could not finish repairing the problem because the following action cannot be completed:  Clearing the DNS cache".  So I contacted my ISP who stated that the DNS cache needed to be flushed/purged thru ipconfig.  So I accessed the command prompt and typed in ipconfig/dnspurge and i also tried ipconfig/dnsflush.  Each time I tried to use ipconfig I would get the following reply:  "ipconfig not recognized as an internal or external command, operable program or batch file".   My ISP was at a loss at that point.  So could someone please help me to correct this situation because I am desperate.  Thanks so much.