I was configuring my ESX whitebox (ESXi 3.5 update 3) and I was having some troubles with installing new VM’s. I was having problems during the installation of Windows 2003 from a mounted ISO. Some files couldn’t be copied during installation:

After I retried to copy the files, it sometimes continued copying, but after a while, I got a nice bluescreen:

From the error’s it is not directly clear that it is a memory problem, but the first thing I tried was to pull out some memory modules. The problems disappeared immediately.

Now this is why VMware advises to test the memory for 72 hours ( you can use Memtest86) before you put an ESX server in production.