what is the EN folder and all the files with numerical extensions and pqi

I have a compaq, and when cleaning up old files I discover this folder on my D drive.
All my internet search brings me more confusion.
What is this EN folder, and all these .002-.049 files and the .pqi files.
It takes alot of space on my hard drive.
Are they really needed.
They are all dated 2001, the year I got this computer.
Thank you