X5 Deleting Arial Fonts

Casual CorelDraw user. Currently using X5, 64 bit and Win 7. Yesterday, while opening an older cdr file ( I believe from version 10 ) I’ve got a message ( warning ) that I do not have fonts installed used in this file and they have to be substituted. Mentioned fonts are default windows Arial fonts. Quickly I realized that X5 not only warned about missing fonts. In fact it deleted them from my windows font folder. 4 Arial types were gone, affecting not only my drawings but many other programs on my computer.
I reinstalled missing fonts. Removed X5 from HD, downloaded the latest X5 version, I believe containing Sp3. No help. Now every time I open CorelDraw I loose after mentioned Arial fonts.
Can anyone help me out solve this problem. I’ve been using X5 for the past few months and used to open older files several times without such problems ever occurring. Thanks
Adam