Q: I keep getting error 3131 when I try to cancel preorders on Windows 8.

Hello, grtdfr. 

Thank you for visiting Apple Support Communities. 

Try signing out of the iTunes Store then back in and test canceling your preorders. 

iTunes 11 for Windows: Manage your iTunes Store account

http://support.apple.com/kb/PH12507

If the issue persists, try the troubleshooting steps in the article below. 

"Error 3000" through "3999"

Alerts with codes in the 3000 range generally mean that iTunes cannot contact the gs.apple.com server on ports 80 or 443. This may be because out-of-date or incorrectly configured security or firewall software is interfering, or due to your Internet proxy settings. If you are using a proxy, try removing the proxy settings, or using a known-good network. If that does not resolve the issue, follow iTunes for Windows: Troubleshooting security software issues.

iTunes: Advanced iTunes Store troubleshooting

http://support.apple.com/kb/ts3297

Cheers,

Jason H.