There is no such file, a number of DLL files instead, some of them:
advapi32
comctl32
comdlg32
gdi32
iphlpapi
kernel32
mapi32
mpr
msimg32
netapi32
odbc32
odbccp32
psapi
rasapi32
rasdlg
sensapi
setupapi
shell32
shlwapi
urlmon
user32
wininet
winmm
winspool.drv
ws2_32
...
Win32api is used as a sort of a universal replacement.
MSDN: If you specify WIN32API for the LibraryName, Visual FoxPro searches for the 32-bit Windows .dll function in
Kernel32.dll,
Gdi32.dll,
User32.dll,
Mpr.dll, and Advapi32.dll.
Using Win32 functions in Visual FoxPro
http://www.news2news.com/vfphttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/fox7help/html/lngdeclare___dll.asp