Step 1 -> open System Preferences -> Keyboard
here we should: Use all F1, F2, etc. as standard function keys. -> Enable
Step 2 -> Open Parallels Desktop -> Preferences
Here we should: MacOS X System Shortcuts -> Enable
Step 3 -> Open Parallels Desktop -> Virtual Machine -> Configure… -> Options -> Advanced
Here we should: Optimise modifier keys for games -> Enable
this makes ctrl,shift,alt keys work properly for Windows
Step 4 -> Open http://pqrs.org/macosx/keyremap4macbook/index.html.en and download/install “KeyRemap4MacBook it is free
Step 5 -> After reboot open System Preferences -> KeyRemap4MacBook ->
Here you should enable :
Change F1…F19 Key & Functional Key … -> Change F1..F19 Key … -> Macbook Series … -> F1,F2…
Change F1…F19 Key & Functional Key … -> Change F1..F19 Key … -> Macbook Series … -> F3,F4 to Expose…
Change F1…F19 Key & Functional Key … -> Change F1..F19 Key … -> Macbook Series … -> F7,F8,F9…
Change F1…F19 Key & Functional Key … -> Change F1..F19 Key … -> Macbook Series … -> F10,F11,F12…
Change Eject Key -> Eject to Forward Delete
Also if you want to Home/End/PgUp/PgDn/Insert/Delete with one hand inside Parallels VM enable this option:
Change Option_R Key … -> Enable