If you are using Windows 95, create a new DWORD-value named MaxConnections (if it doesn't already exist). Modify the value to something higher than 100 (hexidecimal 64). 100 is the default setting.
If you are using Windows 98, create a new String-value named MaxConnections (if it doesn't already exist). Modify the value to something higher than 100 (for example, 256). 100 is the default setting.
After restarting Windows, the problem should be solved. The MaxConnections setting only affects TCP/IP Protocol! In Windows NT, this procedure is not necessary: only adequate available RAM memory--including virtual memory (NT 4.0 minimum 1Gb, Windows 2000 minimum 2Gb). The maximum connections are capped at 12,800 in Windows NT, and at 25,600 in Windows 2000.