Can't install windows

[V1P3R]

A few days ago my desktop PC stopped booting (would get stuck at the windows logo) and when booting in safe mode it would hang for a bit while trying to load CLASSPNP.sys.

The PC had been running perfectly so far and I have installed windows 7 multiple times before on the machine (It was also overclocked, but I removed the overclock a few days ago after I started to have issues).

Specs

• Intel Core 2 Quad Q6600
• Zotac GeForce GTX 480
• OCZ nVIDIA SLI DDR2 PC6400
• MSI P7N SLI Platinum
• Western Digital Caviar SE16 500GB
• Corsair Powersupply 750W

I tried to reinstall windows but now it keeps getting stuck on the completing installation stage.

I have tried the following;

• Tried to install windows 7 from both USB and DVD (Two different ISOs were used).
• Tried to install to a different hard drive.
• Tried a different sata port.
• Currently running memtest86+ (46 hours so far with no errors).
• Tried disconnecting as many usb devices as possible when installing windows.

Does anyone have any idea as to what I should try next?

 

[Orcvader]

Try clearing the CMOS?
Might be the motherboard.

 

[Arterion]

Make sure you don't have an ethernet cable plugged on at the time; there's no reason this should make a difference, but it seems to have done so once or twice for me.

Are you sure it's 'stuck' and not just taking a while?

 

[V1P3R]

Try clearing the CMOS?
Might be the motherboard.

Windows 7 installed fine after clearing the CMOS, Thanks for the help.

Edit: forgot to update this post, the same issue happened the next day where windows would freeze when booting (at the windows logo), turned out to be a faulty wireless card.