"The tomatoes are good."
Translation:टमाटर अच्छे हैं।
I don't know about the Windows keyboard but च्छे(cche) is च-अ+छे = च्+छे.
You will have to type च and then look for the 'halant' sign ् to get च् which is the just the consonant without the अ vowel sign. Then type छे as you normally would (छ with the े sign). They will automatically form the conjunct.