My website was designed by a 3rd party who provided an onsite editor. Each time, I try to up load a document or image from my computer, a prompt appears advising me the mht or htm format is not acceptable. My questions are:
How to bypass the editor and copy and paste banners, docs, images directly on to the website?
How to disable the editor?
How to convert mht and htm formatted documents/images in to gif and jpeg formats?
If there is a need for modification of html, and if yes then how to go about doing it?
(too many questions)

Look forward to hearing from you

Best regards,
Prem Bhandari

Without knowing exactly how the program was designed I would suggest contacting the 3rd party who originally designed the website for you to fix any program errors. Especially if he / she was compensated for their time.