Due to overheads of security algorithms used in IPSec, transferring data using IPSec is known to be significantly slow compared with open system. In this paper, we present new results on performance of IPSec using 7 encryption systems for both IPv4 and IPv6 using Windows 7 and wireless network access. For the system studied, enabling IPSec results in approximately 60% (IPv4) and 48% (IPv6) less TCP throughput compared to open system. Among encryption mechanisms, 3DES-SHA provides the highest TCP bandwidth for IPv4, while 3DES-MD5 gives the best result for IPv6. We also provide the results for UDP.