Paint has stopped working right. It no longer allows me to paste. What’s wrong with it?
Make sure you have the 'select' widget enabled, it's the one with the rectangle around it. Then you can paste.
by painting with white paint
Is the copy paste works on other docs, or only on paint? if you have the difficulty for all then perhaps the clipboard is going wrong
Maybe this microsoft fix it can help
read the solution here if you dont have windows xp cd to get a fresh paint
Apparently there is a tool GetOpenClipboardWindow that can help in identifying why copy paste dont work?