its 4.1e and i used this guide :
-UPDATING TO 4.1-
(A) NECESSITIES:
1. A Wii with an internet connection (wired or wireless).
1. 4.1 Update.rar
2. Clean FAT formatted SD Card.
(B) STEPS:
1. Extract 4.1 Update.rar to the root of your SD Card.
-(If the first two letters of your Wii's serial number are LU: rename 41USAhacks.ini to hacks.ini
if they are LEH: rename 41PALhacks.ini to hacks.ini)
2. Do an officlal Update. (Wii Options, Wii Settings, Wii System Update).
3. Go into Wii Options, Data Management, Channels. It should ask to load boot.elf, do so and install the HomeBrew Channel and BootMii.
-(install BootMii as boot2 if you can, but if not as IOS will work).
4. Launch BootMii*. Click the 4th icon (it looks like gears) and backup your NAND. (Have 528mb free on the SD Card).
5. Go into the HBC, run CMDVDX34. Choose Downgrade IOS35.
-(if it says something about being a pirate, uninstall all your pirat(ed/ing) materials, and run shared2clean from HBC).
-(if it says "failed to add title......", get back into HBC, run WMIOS35, install IOS35-64-v1040.wad, then reboot with the HOME button).
6. Click Exit.
7. Get back into HBC, run WMIOS35, install cios_fix.wad with the + button, then reboot with the HOME button.
-(if you get a -2011 or -1035 error, skip this step and proceed directly to step #8).
8. Make sure the internet connection for your Wii is set up, get back into HBC, run IOS DOWNGRADER V1.1, reboot when it's done.
NOW WE CAN INSTALL WADs
9. Get back into HBC, run WadManager, install CIOS60BF.wad with the + button, then reboot with the HOME button.
10. Get back into HBC, run Preloader. Press 1 to install, now you should be at the Preloader menu**. Set it up as follows:
-Go into Settings, change:
AutoBoot: System Menu
Stop Disc: On
Ignore Standby Mode: On
-then click Save Settings and press B.
-Then go into SystemMenu Hacks, enable AT LEAST these hacks:
"Skip disc update check"
"Remove diag disc check"
"Remove NoCopy Protection"
-The RegionFree hacks are optional and up to you.
-then click Save Settings and press B. Then click System Menu.
11. Get back into HBC, run cmios Installer. Press any button to reboot when finished.
***12. Get back into HBC, run cIOSCORP v3.3 Installer. Press any button to reboot when finished.
13. Get back into HBC, run DVDX Fix Installer (if you want DVDX installed). Press any button to reboot with finished.
*-If you installed as boot2, reboot the Wii and BootMii should boot. If installed as IOS, go into HBC, press Home and click Launch BootMii If installed as boot2, use an NGC controller or the Power/Reset/Eject buttons on the Wii to get through the options, if IOS then NGC Pad only.
**-If it didn't take you to the Preloader menu automatically, turn the Wii off then back on and immediately hold reset.
***-For more info on the cIOSCORP v3.3 and cmios installer, read cIOSCORP readme.txt in root!!!
 LINKS:
1. 4.1 Update.rar -
http://www.tinyurl.com/41update
2. This Guide -
http://www.tinyurl.com/41update
3. BootMii/HackMii Installer Beta2 -
http://bootmii.org/download/
4. BannerBomb -
http://bannerbomb.qoid.us/
5. cIOSCORP v3.3 -
http://gbatemp.net/index.php?showtopic=173466&st=0