Hibiobit,
Thank you for your query, I am happy to assist you.
I grasp that after updating to Windows 8.1 you are experiencing an issue with your Internet connection. Have you tried powering off everything on your network including the router and then starting them back up, beginning with the router first.
Here is a link to a document (from www.mediacollege.com) to override the default DNS server. Change DNS Settings in Windows XP.
To set the DNS for google Preferred DNS server input 173.194.115.18 and the alternate to 173.194.115.17.
Does this make a difference? If the interruptions have ceased, then I suggest calling your router provider to have it checked.
If there is no difference, try a different browser. Here is a link to Troubleshooting Wireless Network and Internet (Windows 8)
If the issue is still persisting, I suggest you do a recovery. Performing an HP System Recovery (Windows 8) and then retry your upgrade. Updating Windows 8 to 8.1.
If it is still unresolved I suggest calling HP support.Please call HP technical support at 800-474-6836. If you live outside the US/Canada Region, please click the link below to get the support number for your region. HP Technical Support Sitemap