1. Ethernet Drivers Chip Sets
2. Ethernet Driver For Msi Motherboard
3. Msi H55m E23 Ethernet Drivers For Mac

Basic install:

Australian fashion magazine Frankie with MSI creator laptops. Drivers and Downloads. Intel® H55 Express Motherboards H55M-E23. MSI H55M-E23 Realtek LAN Driver 5.764.09-10-20 It is highly recommended to always use the most recent driver version available. Try to set a system restore point before installing a device driver.

Install using iBoot + Multibeast 3.10 (UserDSDT) with DSDT-GA-H55M-S2V-F3.aml (works also with DSDT-GA-H55M-S2V-F3.aml and F2 BIOS, thanks Braveheart99).
Select:
1 - Drivers & Bootloaders -> Kexts & Enablers ->DISK: IOAHCIBlockStorageInjector
2 - Customization -> Boot Options: 64-bit Apple Boot Screen
3 - Customization -> Themes: tonymacx86 Classic (optional)
4 - System Utilities: Rebuild Caches
5 - System Utilities: Repair Permissions
NOTE: Don't use VoodooPS2 with DSDT-GA-H55M-S2V-F3.aml.
Lan:
1 - Install Lnx2Mac for LAN.
Sound:
1 - Download the attachment:
2 - Unzip.
3 - Install GigabyteALC888bautoHP.kext in Snow/Extra/Extensions
4 - Download Kext Utility or install from Multibeast.

Ethernet Drivers Chip Sets

5 - Throwing each file into Kext Utility, install AppleHDA.kext (rollback 10.6.2) and HDAEnabler.kext (manual put both files in Snow/System/Libray/Extensions)
6 - Double click in Kext Utility to repair kexts permisssions for system's and Extra folders
7 - Use Mulibeast -> System Utilities to repair permisions and cache.
8 - Restart.
I hope it helps! Works for me in 3 differents disks. Let me know if it work please.
Sorry for my english
EDIT:

Ethernet Driver For Msi Motherboard

LION 10.7.2

Msi H55m E23 Ethernet Drivers For Mac