TEC file extension is associated with a PDP-10 TECO macro file.
Trouble opening TEC files on windows?
Advanced File Optimizer
Need help opening a TEC file? Advanced File Optimizer will do this for you. Opening a TEC file only takes a few clicks and is very easy, even for novice users.
Hey! I am grateful to you guys to make available this wonderful software for free... I was facing some File extension problems for a long time...literally faded up...then found File extension fix application from this site and error disappear... really cool:)
Anna
I am very delighted to have this software...it's really a fast, efficient and safe solution to rid your File extension errors forever!
Pmm_003
It is the best and most effective product to fix error, I have ever use...highly recommended!!
TEC file extension is associated with a PDP-10 TECO macro file. 
Ben Aldrin
Thank you man it works