Word 2007 can't copy and paste

Word had worked well in Windows 7, but now, after I moved to Windows 8.1 almost everything is messed up. Most annoying thing is the copy-paste function. When I try to copy something, it can't be copied to the clipboard and some weird cursor appears when I click where to paste. When I try to cut, the string is saved in clipboard and it works fine.

Also, when I run Word in safe mode, all the functions work fine (even copy-paste).

Does anybody know what should I do? I tried Office Diagnostics, but it shows 0 errors.

Hey mate. Make sure it is fully updated, and windows is fully updated. Aside from that, you can attempt a repair: Repair Office programs - Word - Office.com