Hi All,
Just wanted to share my experience in getting as close to a clean install of windows 8 pro. A full clean install i.e.., boot directly from USB or DVD/CD drive, delete and re-format all partitions, and install windows 8 pro is still not possible. I have searched extensively on Google, but until someone develops a hack to change/bypass the product key in bios/motherboard, this is not possible.
Disclaimer: Do at your own Risk!! It worked for me; but if you have never done istallations, this is probably not the ideal 1st time experience 
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What I have managed is to re-install windows 8 pro from within windows 8 std. Delete, windows.0ld folder resulting in a fairly clean windows 8 pro, with 18.5 GB FREE disk space on C:\ !!! No ACER bloatware. Of course there is another 400MB unused partition (formerly restore partition) that I was unable to merge to C:\. If someone wants to attempt to regain 400MB using partition magic or other tools please post your success. For now I just formatted it as another volume and will use for document storage.
Needed software:
1. Brought windows 8 prog uprage for $40. Downloaded software and created an USB bootable memory stick. Just follow instructions on Microsoft site after purchase. I did this from the Acer W510, but this step can be done from any computer.
2. Download intel processor drivers from here http://us.acer.com/ac/en/US/content/drivers. There is a latest one released today (1/8/13). I put this on another usb memory stick. Note: micro SD cards will not work after windows 8 re-install so this needs to be on another usb memory stick.
Needed Hardware:
1. USB hub - You will need to attach mouse in addition to usb stick/CD ROM
2. USB memory stick of atleast 3GB
Disk Cleanup:
Next windows needs atleast 16 GB free. So nuke your old restores points (from control panel). Also disable Restores.
Next disable hibernation. Open command prompt in administrator mode, and type "powercfg -h off" and then hit enter.
Next right click on C:\ from windows explorer, go to properties and do a disk cleanup. Click on the "clean up system files" and it will give you more cleanup options. Select all and hit OK.
For me this freed up around 16.8GB. If some of you can't get there, start un-installing programs and apps. Finally start deleting files/folders from "program Files" "OEM" etc till you get to 16 gb free. DON'T touch anything under WINDOWS folder...just FYI .
Install windows 8 pro:
The only way to do this is to launch setup from within windows 8 std.
Important: Go to power options under control panel and disable "turning off display" and "sleep" options when plugged in. If not it will go to sleep in middle of installation. Do this unless you want to keep touching screen every 5 minutes!! for next 1 hour.
Open up file explorer, browse to your media and run setup. Follow instructions on screen. It will first load files, restart few times and finally you will get to a bare windows 8 pro. Don't panic if touch screen, wifi, sd card wont work. This is normal. The micro usb and the connected usb hub will work. So use your mouse for the remaining steps:
Now do disk clean up again, selecting "clean up system files". This will remove the windows.old folder and other installations files that are not needed.
Install intel drivers:
Just run the executable that you downloaded earlier from Acer site. Follow instructions on screen.
You are done. All this for about 10GB for free space....I know, lot of work; but that is almost 32% of your disk capacity. Totally worth it for me!!
