per connection. The Dial-Up Networking improvements are also available in Windows 95 OSR2 and are downloadable for earlier Windows 95 releases. For networked computers that have user profiles enabled, Windows 98 introduces Microsoft Family Logon which lists all users that have been configured for that computer, enabling users to simply select their names from a list rather than having to type them in. Windows 98 supports IrDA 3.0 which specifies both Serial Infrared Devices and Fast Infrared devices, which are capable of sending and receiving data at 4 Mbit/s. Infrared Recipient, a new application for transferring files through an infrared connection is included. The IrDA stack in Windows 98 supports networking profiles over the IrCOMM kernel-mode driver. Windows 98 also has built-in support for browsing Distributed File System trees on Server Message Block shares such as Windows NT servers. UPnP and NAT traversal APIs can be installed on Windows 98 by installing the Windows XP Network Setup Wizard. An L2TP/IPsec VPN client can also be downloaded. By installing Active Directory Client Extensions, Windows 98 can take advantage of several Windows 2000 Active Directory features. Improvements to the system and built-in utilities Performance improvements Windows 95 introduced the 32-bit, protected-mode cache driver VCACHE (replacing SMARTDrv) to cache the most recently accessed information from the hard drive in memory, divided into chunks. However, the cache parameters needed manual tuning as it degraded performance by consuming too much memory and not releasing it quickly enough, forcing paging to occur far too early. The Windows 98 VCACHE cache size management for disk and network access, CD-ROM access and paging is more dynamic compared to Windows 95, resulting in no tuning being required for cache parameters. On the FAT32 file system, Windows 98 has a performance feature called MapCache that can run applications from the disk cache itself if the code pages of executable files are aligned/mapped on 4K boundaries, instead of copying them to virtual memory. This results in more memory being available to run applications, and lesser usage of the swap file. Windows 98 registry handling is more robust than Windows 95 to avoid corruption and there are several enhancements to eliminate limitations and improve registry performance. The Windows 95 registry key size limitation of 64 KB is gone. The registry uses less memory and has better caching. Disk Defragmenter has been improved to rearrange program files that are frequently used to a