Just how much RAM does 32-bit Windows support?

Dennis o'reilly By Dennis O’Reilly

In his Sept. 25 lead story, associate editor Stuart Johnston reported that the 32-bit version of Windows Vista provides users with “only 3GB of memory, a limitation that the 64-bit edition doesn’t have.”

Other 32-bit operating systems have similar memory constraints, but Stuart pointed out that 64-bit versions of Vista can address 8GB to 128GB of RAM, depending on the edition (Home Basic, Business, Enterprise, or Ultimate).

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Several subscribers commented that the total amount of addressable RAM on 32-bit systems is 4GB, not 3GB. Reader K. Boriskin explains it this way:
  • “The various versions [of Windows] reported 3GB because that’s all that was available to the user. The rest is used internally for housekeeping, which certainly makes it supported. That has been fixed with [32-bit] Vista SP1, which now reports all installed memory up to 4GB.

    “See, for a start, [Microsoft Knowledge Base] article 946003.”
Stuart’s story was referring to the practical RAM limit — the amount of memory that’s available for applications after the OS claims 1GB. But it’s always a good idea to clarify the difference between this usable memory and the total memory that may be installed on a motherboard.

Password-cracking utility sets off false alarms

Contributing editor Ryan Russell’s Sept. 25 column in our paid content reviewed the free Cain & Abel utility. This program is designed to find and reveal all the passwords that are stored on a PC’s hard disk, which can be useful to legitimate admins as well as nefarious intruders.

It’s understandable that such a program would trigger alerts from your antivirus application. Unfortunately, several readers begged off downloading the program as a result of such antivirus alerts. Brett Shand writes:
  • “FYI, Cain & Abel is producing a hit with Avast AV for [the] Win32:Oliga Trojan. It’s probably a false positive, and the forums have a reassuring reply from the coders that the program can be whitelisted. But I’m not game, especially for this type of software.”
Few programs are indispensable. If your suspicions are raised about any application, leave it be. However, we’re confident that the program Ryan recommended is safe to use and malware-free. In fact, that goes for all the products we review.

In a future Perimeter Scan column, Ryan will examine in greater detail the issue of antivirus false positives. Stay tuned!

Readers K. Boriskin and Brett Shand will each receive a gift certificate for a book, CD, or DVD of their choice for sending tips we printed. Send us your tips via the Windows Secrets contact page.

The Known Issues column brings you readers’ comments on our recent articles. Dennis O’Reilly is technical editor of WindowsSecrets.com.