The letters in INSTALLS make 141 words of two letters or more. The longest is INSTALLS at 8 letters, and the highest-scoring is INSTALLS at 8 points.
No other single word uses all 8 letters of INSTALLS. INSTALLS has 8 letters: 2 vowels and 6 consonants, worth 8 points before any board bonuses.
8-letter words 1
7-letter words 2
install7instals7
6-letter words 9
instal6saints6satins6slants6snails6stains6stalls6stills6tallis6
5-letter words 33
alist5anils5antis5lasts5lilts5lints5lists5litas5nails5nills5sails5sains5saint5salts5sasin5satin5satis5sials5sills5silts5sisal5slain5slant5slats5slits5snail5snits5stain5stall5still5tails5tains5tills5
4-letter words 49
ails4ains4aits4alit4alls4alts4anil4anis4anti4ants4ills4lain4lass4last4lati4lats4lilt4lins4lint4list4lits4nail4nill4nils4nits4sail4sain4sall4sals4salt4sans4sati4sial4sill4silt4sins4sits4slat4slit4snit4tail4tain4tali4tall4tans4tass4till4tils4tins4
3-letter words 29
ail3ain3ais3ait3all3als3alt3ani3ant3ill3ins3its3las3lat3lin3lis3lit3nil3nit3sal3sat3sin3sis3sit3tan3tas3til3tin3tis3
2-letter words 18
ai2al2an2as2at2in2is2it2la2li2ln2ls2na2si2ss2ta2ti2ts2
Words are from our open word list and include some game-only words. Rude words are left out of this page; the unscrambler shows every valid word, lets you add blank tiles and filter by length.