The TFTPDWIN software is a multithreaded TFTP protocol server for Windows 98/Me/2000/XP/2003 that is capable of transmitting and receiving both binary files and text files. It can support large number of transmissions simultaneously. Data about each transmission are displayed on the transmission list, as well as recorded in a log file. A flexible built-in security mechanism enables the administrator to define various conditions under which a transmission may be initiated, including a list of eligible host IP addresses and a list of files that may be transmitted. The TFTPDWIN program supports the blksize, timeout and tsize extended TFTP protocol options. It can transmit and receive files larger then 32 MB. TFTPDWIN is compatible with RFC 1350, RFC 2347, RFC 2348 and RFC 2349 documents. Additionally the TFTPDWIN packet includes a TFTP client program.