c# - Interop.Word.Document.Words border changes very slow -

hi!

i'm working on ms word addin marks words in given text. unfortunately, operation slow. in document of 50 pages (~26'000 words) changing border style 1'100 words takes 15 minutes.

i turned of screenupdating, not help!

here's i'm doing:

using microsoft.office.interop.word; ..... words words = globals.thisaddin.application.activedocument.words; words[i].borders.outsidelinestyle = microsoft.office.interop.word.wdlinestyle.wdlinestylesingle; words[i].borders.outsidelinewidth = microsoft.office.interop.word.wdlinewidth.wdlinewidth100pt; words[i].borders.outsidecolor = microsoft.office.interop.word.wdcolor.wdcolordarkteal; 

what makes slow? can speed things up?