If you don't find Paint on the Start Menu, if this is a recent issue, try
using System Restore to take you back to a time when you had it. Start\All
Programs\Accessories\System Tools\System Restore.
If that doesn't resolve it, open Control Panel, open Add/Remove Programs in
Control Panel, click Add/Remove Windows Components, select Accessories,
click Details, on the pane that opens, select Accessories, click Details,
place a check next to Paint and click OK. If there is a check next to
Paint, remove it, click ok, then replace it and click ok.