When I start my SP3, windows starts Search Filter Host which uses about 30% of the CPU, runs the fan and makes the surface run very warm (not hot). On Saturday, The process would run for hours. Indexing had completed, close to 50K items. But then at start, Windows would start indexing and run the Search Filter Host. Indexing would not complete, while on battery (about 3.5 hours and a drained battery), but would eventually complete when plugged in. Indexing would complete faster when plugged in (about 30 minutes and not doing anything) I tried rebuilding the index. It didn't work. I recovered the PC from factory defaults. It didn't work. I've now modified the directories being indexed to limit it to two directories (onenote a onedrive), which contains about 20K items in the index. With the smaller index, the process will now run for about 30-45 mins and drains the battery about 30%.