I did a major rebuild last year which included Samsung 830 series 128Gb SSD as OS, apps and programs plus 1tb WD HDD as storage. Samsung Magician shows that AHCI is not enabled and suggests that this is slowing the PC. Device Manager shows IDE ATA/ATAPI Controllers as; Intel(R) 7 Series/C216 Chipset Family SATA AHCI Controller. Registry value under HKEY_LOCAL_MACHINE/ system/ CurrentControlSet/ services/ msahci/ start/ value is 0. This has not been changed since time of installation. BIOS has not been flashed/ updated. System; Mobo Asus Sabertooth Z77, Drives as above, 16Gb DDR3 GSkill RAM, GTX660Ti graphics card, Ivy Bridge 3750K processor, Asus Xonar Essence STX sound card, Windows Experience Index shows all components at 7.9 except processor which is 7.6. Fractal Design Define R4 61GB of unused space remaining on the 128Gb Samsung SSD primary drive. This machine has definitely slowed considerably in the past couple of months and I can't find why. Any assistance would be appreciated.