finddll is a command-line tool that scans all current processes on the system looking for the DLL you specify on the command line.
It outputs the PID in both hex and decimal, plus the DLL name and base address for each process where it's loaded. DLL name fragments are supported.
D:\>finddll Wininet Scanning running processes for module: wininet 0x06C8 (1736) SVCHOST.EXE c:\windows\system32\wininet.dll 0x3D930000 0x04CC (1228) SVCHOST.EXE c:\windows\system32\wininet.dll 0x3D930000 0x0618 (1560) Explorer.EXE c:\windows\system32\wininet.dll 0x3D930000 0x0A70 (2672) Skype.exe c:\windows\system32\wininet.dll 0x3D930000 0x0DC4 (3524) skypePM.exe c:\windows\system32\wininet.dll 0x3D930000 0x0E94 (3732) TrueCrypt.exe c:\windows\system32\wininet.dll 0x3D930000 0x0CCC (3276) vmware.exe c:\windows\system32\wininet.dll 0x3D930000 0x13F4 (5108) firefox.exe c:\windows\system32\wininet.dll 0x3D930000