Why is Windows 7 so slow?

After I’ve been looking for a solution for my wife’s new 64 bit gamer PC for some time (and still haven’t found a satisfactory solution), these proposed solutions may or may not work (use at your own risk):
Windows Shell:

• Shell Extensions:
• Run Auturuns.exe or ShellExView.
• Disable/uninstall etc extensions/programs that are started automatically.
• Some that may be disabled as an attempt:
• Nero/Nero Scout.
• VirtualCloneDrive
• Power Archiver 2011
• Optimizing folders for images/videos etc.
• Windows is continuously trying to optimize your folders for whatever is in them, but that process is quite expensive.
• Set all folders to be optimized for “General Items”, then you can set the ones you want to be optimized for other stuff to whatever as you wish (and at a performance cost) afterwards.
• Windows Search Index
• Disable/turn off.
• Antivirus software real time protection.
• Turn off (at own risk)
• User profile issues
• You may have an issue with your user account. Try to create a new user account, and check if that account has the same problems.

Internet Explorer:

• Turn off addons.
• To run without addons, start IE using “iexplore.exe –extoff” in Start/Run.

Firefox:

• Is maintaining a 50M+ database of malicious web sites which is synchronized (at startup maybe? or in the background?).
• May be turned off (at your own risk) if you have healthy browsing habits and don’t click just any links.
• Turn off addons.

Source(s):

• http://social.technet.microsoft.com/Forums/en-US/w7itproperf/thread/4ec1ab74-f043-4120-9f27-d4b09b51e643/

UPDATE:
The reason the PC was so slow seems to be the SSD disk on which Windows is installed. Googling it turned up several people with problems, and also some guy at the retailer (Komplett.no) confirmed that there could be some issues with it. Now just waiting for my wife to make her backups so we can return the PC to the retailer for repairs.