You will need to do some more investigation into just what is happening when you invoke the the text editor to be sure, the process monitor I linked above will help here if your I.T. will let you use it.
If you run it and watch what is happening when you go to edit a text it will show just what files are being looked at or opened and slowing things down.
Before that though you could check how many fonts are in your server directory, if you have reloaded things after a virus clean up then you may find that you have multiple copies of the font definitions that Atocad has to search through - get rid of any duplicates.
(CCleaner can help find and delete duplicate files).
Also try turning the Communication Centre off; follow the instructions in my previous link.
Thinking more since my previous post I think I've seen a problem some years ago where the text editor was scanning the whole autocad help file before opening for some reason.
I'll see if I can find that again, but again you would probably need Process Monitor to confirm this.
Im intelligent enough to know that I dont know everything; but I'll tell you all about it anyway.