To do it you need to hotkey a shield and have two identical, unenchanted, unsmithed, one-handed weapons hotkeyed to another key. With two identical non-upgraded weapons hotkeyed you can dual wield them really quickly by pressing the hotkey twice. While they are equiped you can easily switch to a shield and back by hitting the shield hotkey and then they weapon hotkey again.

I've been doing this with a new character who doesn't use enchanted/smithed weapons and rapidly switching between a shield / dual wield. What I found is that if you hold the block button (normally right-click on PC) and then hit the hotkey to get your second weapon out the second weapon will now be in blocking mode and will block enemy attacks. The only difference between this style of blocking and shield/two-handed blocking is you can't bash and instead perform a swipe or power swipe.

I havn't checked other means to perform this such as if you bring up the favourite weapons and do switches that way if it will allow blocking in dual wield if someone else wants to check.

TL;DR

• Hotkey identical non-upgraded one-handed weapons to one key
  
• Hotkey a shield
  
• While holding a shield go into block mode and hold it
  
• While in block mode use weapon hotkey to bring out other weapon
  
• You are now blocking while dual wielding

OPTIONAL: Use attack button while in this mode to perform a swipe attack or swipe power attack with your left hand (blocking weapon)

Very cool, but pretty useless.

I can't wait for the Unnecessary Violence mod to be made for Skyrim. That will be epic.

Very nice find indeed,i wanted to test...but it's impossible now.

Good exploit. Hopefully the modders will create a better fix for the blocking issues in this game. Maybe even implement a parry feature.

to much work il stick to my slash and retreat strategy

Pretty much, it's useless =) I was surprised to see it there though and there is clear distinct animations for blocking in dual wield so it's in the game if any modders want to make use of it without needing to do much.

Its not even worth blocking its easier to just dodge attacks.

Exactly. And besides of that, it makes pretty good sense that you can not block with 2 one handed. This exploit is rather useless.