Sony VAIO PCV-RZ54G
Pentium 4 Processor
Motherboard ASUSTek P4SD-VL
Installed Memory: 1.5 GB (2x256 and 2x512) DDR PC3200
Maximum: 2GB DDR PC3200

I recently bought a 1 GB kit of memory that was supposed to be compatible with the Sony PCV-RZ54G. When I opened my computer, I had two 256 sticks installed in DIMM0 and DIMM2. DIMM1 and DIMM3 were open. I moved the two 256 sticks to DIMM2 & DIMM3, and installed the two 512 sticks in DIMM0 & DIMM1.

Since doing the upgrade, I'm having a number of problems:
1. The Faster User Switching in XP no longer works. If you are logged in as one user and try to switch to another, you're simply taken back to the welcome screen after entering the password of the second user. You have to log out of the first user's account, then you are able to log onto the second user.
2. Sometimes, when you log on to any user, explorer.exe doesn't start. I have to open Task Manager and manually start the process.
3. None of the limited accounts can access Flash content on websites. It says Flash isn't installed. I've tried "installing" it, but that doesn't work. Also, if I log in under my administrator's account, I'm able to access Flash content as normal.
4. Updating my AVG, using Windows Updates, or updating other anti-spyware apps is hit-and-miss. Sometimes, the updates are successful; sometimes, they aren't.

I ran CPU-Z. I've taken screenshots and put them in a Word doc. I've attached this doc to my post. I did make a mistake in the last screenshot. I took two screenshots of the screen for DIMM2. However, the screens for DIMM2 and DIMM3 are exactly the same, so this shouldn't matter.

I've done a few upgrades on my systems in the past, but this is my first attempt at a memory upgrade. Any help would be much appreciated. Thanks in advance.

Have you tried putting the original memory modules back into their original DIMM sockets and pulled the new memory out?

This would tell you if your new memory is the culprit.

try his idea. if that doesn't work you may try switching the modules around. put the original ram bac in the original spots and then add the new ram to the remaining slots.