Zoho Docs - Desktop Sync

Zoho Docs - Desktop Sync

Dear Team,

I have installed the application on my system (Windows XP). And all my docs in my zoho docs got synced into my computer. But i can't able to open/edit in my systems Excel software. 

Whenever i opened the files, it re-direct to zoho docs webpage. Then how can i work in offline and sync when i'm online. 

Regards,
Aghil