Here's the system: Athlon64 3500, ECS RS482-M (board), XPSP2 updated as of ~June 1st (whenever the last patch cycle was). The system came new with a fresh install of Windows. I already had an XP installation on another hdd I wanted to use, so I swapped the new drive for the old one. Had to boot in safe mode first time and find a few drivers (smbus, ati, etc.). The last driver I added was for the processor (stock AMD install utility). All hardware is now properly recognized by Windows. However, the system will not boot into normal mode (I can use safe mode, however). On cold boot it begins loading XP (the little flag logo), but as soon as that ends it reboots. Checking eventvwr.msc, i see that the scm fails to load the driver for amdk8 (I assume the file is amdk8.sys), along with fips and two symantec components. What bothers me is the problem with the CPU driver. I am using the latest version off the AMD website and its in the drivers folder. Device manager and all similar references report the correct CPU. No kernel dump or anything - just the event log entry. Ideas?

I believe the CPU driver that you mentioned is for Cool'n'Quiet. You don't have to install it unless you plan on using it & if you're a gamer, you may find that it causes problems. You can't just swap a HDD with WinXP pre-installed from another system...have to do a "repair install". http://www.microsoft.com/windowsxp/using/helpandsupport/learnmore/tips/doug92.mspx

Thanks, I may take the pill.

Update... There is an AMD64 processor driver - per my experience it appears that this is necessary for a default install of XP (curent version 1.3.x). Exactly why this is required probably either has to do with the AMD64 memory controller or the expanded global registers. Essentially, if the scm fails to identify the processor, it defaults to safe mode operation and uses the generic x86 driver. Ironically, if the scm misidentified the processor it would probably allow a normal boot. (The CPU driver is loaded relatively early in the boot process and is used to run the idle loop). The CoolnQuiet interface is, as mentioned above, a separate and optional app. Look for the regular processor driver.