IFSHLP.SYS
（重定向自Installable File System Manager）
IFSHLP.SYS (the Installable File System Helper) is a MS-DOS device driver that was first released as part of Microsoft Windows 3.11. It enables native 32-bit file access in Windows 386 Enhanced Mode by bypassing the 16-bit DOS API and ensuring that no other real mode driver intercepts INT 21h calls.