Moved to Mobile section.
Assuming you're talking about replacing or upgrading the processor in a Laptop/Notebook computer (the part number you posted is that of a mobile Athlon XP-M), i recommend you contact your Laptop's manufacturer and ask them about any possible upgrades and more importantly whether they have released any updated BIOS-versions to support newer processors.
Generally, replacing your current CPU with a part of the same OPN (Ordering part number, i.e. 'AXMH1800FQQ3C'
will be no problem.
Theoretically, any (mobile) Socket A processor with an OPN that starts with 'AXMH
...', i.e. 45W Mainstream parts, should work with your machine although it can't be guaranteed if there is no BIOS-support.
The opinions expressed above do not represent those of Advanced Micro Devices or any of their affiliates.
AMD Athlon 64 X2 6000+ 89W :: Asus M2N32SLI Deluxe :: 2x1024MB Muskin XP2-6400 DDR2-800 :: BeQuiet! Darkpower Pro 530W :: 2x WD Raptor 74GB/10k rpm, RAID 0 :: ATI Radeon X1950XTX