If you use TeamViewer to access another PC remotely over the internet, you're probably still using version 6 or 7. At the start of this month, version 8 was released. This includes lots of new features and fixes, including full Windows 8 compatibility, so it's a good idea to upgrade.
As always, TeamViewer is free for personal use, which is a good deal as it starts from around $500 for corporate users. The download from www.teamviewer.com is a 6 MB file, and VirusTotal says it's free of malware and viruses and thus perfectly safe to use.