Windows Vista Beta 2, released last week, includes a new security feature designed to protect against buffer overrun exploits. Called Address Space Layout Randomization (ASLR), the feature loads key system files in different memory locations each time the PC starts, making it harder for malicious code to run, according to Microsoft. “It is not a panacea, it is not a replacement for insecure code,” Michael Howard, a senior security program manager at Microsoft, wrote in a blog post announcing the feature.