Hello all, I am currently trying to install Windows Server 2012 R2 Essentials on a Dell Dimension 5100 with Intel Pentium 4 processor, and get the following error: Your PC needs to restart. Please hold down the power button ... Error Code:0x000000C4 I looked this up, and found info relating to an unsupported CPU. I looked up my processor info and get this: Intel(R) Pentium(R) 4 CPU 2.80GHz Intel64 Family 15 Model 4 Stepping 1, GenuineIntel HTT * Hyperthreading enabled HYPERVISOR - Hypervisor is present VMX - Supports Intel hardware-assisted virtualization SVM - Supports AMD hardware-assisted virtualization EM64T * Supports 64-bit mode SMX - Supports Intel trusted execution SKINIT - Supports AMD SKINIT EIST - Supports Enhanced Intel Speedstep NX * Supports no-execute page protection PAGE1GB - Supports 1 GB large pages PAE * Supports > 32-bit physical addresses PAT * Supports Page Attribute Table PSE * Supports 4 MB pages PSE36 * Supports > 32-bit address 4 MB pages PGE * Supports global bit in page tables SS * Supports bus snooping for cache operations VME * Supports Virtual-8086 mode FPU * Implements i387 floating point instructions MMX * Supports MMX instruction set MMXEXT - Implements AMD MMX extensions 3DNOW - Supports 3DNow! instructions 3DNOWEXT - Supports 3DNow! extension instructions SSE * Supports Streaming SIMD Extensions SSE2 * Supports Streaming SIMD Extensions 2 SSE3 * Supports Streaming SIMD Extensions 3 SSSE3 - Supports Supplemental SIMD Extensions 3 SSE4.1 - Supports Streaming SIMD Extensions 4.1 SSE4.2 - Supports Streaming SIMD Extensions 4.2 AES - Supports AES extensions AVX - Supports AVX intruction extensions FMA - Supports FMA extensions using YMM state MSR * Implements RDMSR/WRMSR instructions MTTR * Supports Memory Type Range Registers XSAVE - Supports XSAVE/XRSTOR instructions OSXSAVE - Supports XSETBV/XGETBV instructions CMOV * Supports CMOVcc instruction CLFSH * Supports CLFLUSH instruction CX8 * Supports compare and exchange 8-byte instructions CX16 * Supprots CMPXCHG16B instruction DCA - Supports prefetch from memory-mapped device F16C - Supports half-precision instruction FXSR * Supports FXSAVE/FXSTOR instructions FFXSR - Supports optimized FXSAVE/FSRSTOR instruction MONITOR * Supports MONITOR and MWAIT instructions MOVBE - Supports MOVBE instruction PCLULDQ - Supports PCLMULDQ instruction POPCNT - Supports POPCNT instruction SEP * Supports fast system call instructions DE * Supports I/O breakpoints including CR4.DE DTES64 * Can write history of 64-bit branch addresses DS * Implements memory-resident debug buffer DS-CPL * Supports Debug Store feature with CPL PCID - Supports PCIDs and settable CR4.PCIDE PDCM - Supports Performance Capabilities MSR RDTSCP - Supports RDTSCP instruction TSC * Supports RDTSC instruction TSC-DEADLINE - Local APIC supports one-shot deadline timer TSC-INVARIANT - TSC runs at constant rate xTPR * Supports disabling task priority messages ACPI * Implements MSR for power management TM * Implements thermal monitor circuitry TM2 - Implements Thermal Monitor 2 control APIC * Implements software-accessible local APIC x2APIC - Supports x2APIC CNXT-ID * L1 data cache mode adaptive or BIOS MCE * Supports Machine Check, INT18 and CR4.MCE MCA * Implements Machine Check Architecture PBE * Supports use of FERR#/PBE# pin PSN - Implements 96-bit processor serial number Logical to Physical Processor Map: ** Physical Processor 0 (Hyperthreaded) Logical Processor to Socket Map: ** Socket 0 Logical Processor to NUMA Node Map: ** NUMA Node 0 Logical Processor to Cache Map: ** Data Cache 0, Level 1, 16 KB, Assoc 8, LineSize 64 ** Unified Cache 0, Level 2, 1 MB, Assoc 8, LineSize 128 Logical Processor to Group Map: ** Group 0 As far as I can see, this processor should support the Server 2012 R2 installation. Is there anything further I can do to get this up and running? I previously had Server 2012 up and running on this machine, but removed it for a clean installation.