I have yet to use this app, but apparently it works well, from what I heard.
TeamViewer Portable 5.0.7904 has been released. TeamViewer is a remote PC support/control and screen-sharing tool. You can remote control a partner’s desktop to give online assistance, or you can show your screen to a customer without worrying about firewalls, IP addresses and NAT. This release updates TeamViewer to the latest version and adds multilingual support. It’s packaged as a portable app so you can work on the go and it’s in PortableApps.com Format so it can easily integrate with the PortableApps.com Suite. It’s released as freeware for personal, education and non-profit use (business use requires a license).
I have listed some features below.
– Support, administration and screen-sharing in one package
– Remote administration of unattended servers
– File transfer
– Key exchange and AES (256 Bit) session encoding
– Remote support without installation
– Remote presentation of products, solutions and services
– Works behind firewalls
So if you want to help your parents out with an issue, this is the application to try.