Google Input Tools support various languages including Nepal for Nepali language input or keyboard in natural Unicode layout.
Click here to type in Google Input Tool Nepali
Click here to download Google Input Tool Nepali Offline (गुगल इन्पुट टुल डाउनलोड गर्न यँहा क्लिक गर्नुहोस्)
First download and install: 1. Must Install me (GoogleInputTools).exe
Second download and install: 2. Google Input Nepali.exe