Dell Latitude D600: swapped the CPU to Intel Pentium M 770(2.13Ghz) from Intel Pentium M 725(1.6Ghz) (2GB RAM) HP Pavilion a730n: swapped the CPU to Intel Pentium 4 HT 650(3.4Ghz) from Intel Pentium 4 HT 530(3.0Ghz) (4GB RAM) Currently, D600 is running 32bit and a730n is running 64bit Windows 8 Enterprise and Office 2013 Pro Plus.