The machine originally came with windows 7 and during the remanufacturing process Windows 10 Pro was installed on top of the old Windows 7 without first removing the old system. This created a conflict that slowed the machine down slower than the old Dell I was replacing that only has 4 gigs of ram where as the new Dell 990 comes with 16 gigs of ram.The conflict is occurring when opening programs that were written to operate with both systems such as Office 13.