Ask DACS
April 2009

Moderated and reported by Jim Scheef.

Ask DACS is a question and answer session held at the start of the monthly general meeting. We solicit questions from the floor and by email (AskDACS@dacs.org). Hopefully we find the answers from those present at the meeting.

AskDACS is the regular Question and Answer session before the main presentation at the monthly General Meeting. We solicit questions from the floor and then answers from other audience members. My role as moderator is to try to guide the discussion to a likely solution to the problem. The recording this month was quite garbled, so much of this article is from memory and some specifics will be missing.

We had one question submitted by email:

Q – My computer runs Windows XP Home Edition with 256 MB RAM. System scans with AVG or Ad-Aware or Spybot often bring up the warning: "Windows - Virtual memory minimum too low." "Your system is low on virtual memory. Windows is increasing the size of your virtual memory paging file. During this process, memory requests for some applications may be denied. For more information, see Help." Does this mean that my computer is, or is not, dealing with the load? Does "see Help" refer to that which is on the Start menu? Restart/warm boot does not appear to reset the memory.

A – There are two questions here. The answer to the first question is: “Sort of.” Your system needs more memory space and is trying to adapt by creating more.

Now that new computers routinely come with 1G, 2G or even 4G (the maximum for the 32-bit version of XP) of system RAM, a system with 256M seems under-equipped, but the truth is that XP will run with as little as 64M of RAM. It will run slowly, but it will boot and run. The message indicates that the system is under stress in that the programs running (both the ones you can see and the background processes) want more RAM than is currently available. Windows is increasing the size of the virtual memory paging file (aka: the swap file) to create more “fake” RAM. The answer to the second question is “yes,” the message refers to the Windows Help file. Good luck finding anything really useful. For a discussion of how virtual memory works, see Wikipedia (http://en.wikipedia.org/wiki/Virtual_memory).

Beyond the original questions, the discussion continued on how to buy additional RAM. To distill the discussion, first find the type of RAM required. All current machines use RAM chips mounting on a dual inline memory module (DIMM). The specifications for RAM include the memory bus speed, and esoteric timing requirements. RAM can be buffered or unbuffered, ECC (error correcting code) or not, and have varying voltage requirements. So it is best to determine what your system needs from the user manual for the system board or an online resource like Kingston. (Ah, for the days when RAM was either PC-66, PC-100 or PC-133 and that was it!)

Kingston Technology (http://kingston.com) and (http://Crucial.com) are major sellers of brand name RAM modules and offers tools on their websites to determine the exact specification used by your system. These are good resources. New Egg (http://newegg.com) and others were also mentioned. Sources mentioned for buying RAM included Tiger Direct, New Egg, and others. Once you have determined the exact specification needed for your system, you are ready to comparison shop.

Q – The next question was also sent in my email, but it was sent to Rob Limbaugh, DACS President. The questioner wants to know if opening “Network Neighborhood” or “My Network Places” in the Windows Start Menu exposes their computer to the Internet. In other words, is browsing the network “risky behavior”. The situation is a single computer connected to a hardware router and then to a DSL or cable modem connection to the Internet.

A – The simple answer to this question is “no.” This assumes that the router is properly configured to create a private network using a non-routable network address like 192.168.x.y with a netmask of 255.255.255.0. Any values of x and y will be non-routable on the Internet which means that someone out afar cannot enter an address like 192.169.1.88 and open a connection to your computer. Naturally, there are exceptions to this. The biggest exception is when you have a wireless (Wi-Fi) network. Anyone connecting to your wireless network, including your neighbors, is inside the firewall created by your router and/or access point (AP). This means that your computers are exposed to their whims. This is why it is best to run a personal firewall on your computer (even the firewall included with XP) when you have a wireless network and a hardware firewall in your router.

Q – A follow up question: Why does my computer sometimes connect to your neighbor’s wireless network rather than my own? Shouldn’t the signal from my access point be the stronger signal?

A – Among the possibilities mentioned by members in the audience: interference for walls, furniture or appliances in your house between your computer and your AP (access point). The possibilities for a misconnection are greatest when both of the access points involved are not secured in any way. If you are using Windows to configure your wireless connection rather than a utility from the Wi-Fi card manufacturer, then it should be easy to prevent a connection to your neighbor’s network. Open the properties dialog for your wireless connection. Click the Advanced button and make sure the “Automatically connect to non-preferred networks” is unchecked. This will force you to approve any connection to a new network. Also select the “Access point (infrastructure) networks only radio button. This will help prevent accidental connections to another computer when in a coffee shop or other public place. Close that dialog. Next find your network in the list of Preferred networks and move it to the top. This will give priority to your network. Next scroll thru the list a remove any network you cannot identify. Last, find your neighbor’s network and select it; click the Properties button. On the Properties dialog, click the Connect tab and uncheck the box “Connect when this network is in range.” Click OK and OK to close all dialogs. This will prevent an automatic connection to your neighbor’s network when that is the stronger signal.

Finally, your wireless AP should be secured using the best encryption supported by both your AP and your computer. WPA is far better than WEP. Another layer of security is MAC filtering. Enabling this requires registering your computer’s wireless card in your router’s firmware by it’s unique MAC address. This seemingly redundant security procedure prevents your neighbor from accidentally connecting to your network by allowing your router to connect only to known computers. The MAC address is a number printed on the card or your computer that looks like 00-A0-BC-0A-B5-69.

One last point not covered at the meeting: There are only three channels that should be used for all wireless networks – channels 1, 6 or 11. Using any other channel will result in radio interference between neighboring networks. Make sure you and your neighbors do not use the same channel. It can be difficult in an apartment building to ensure that each AP is set to one of these three channels yet with no adjacent AP’s on the same channel. This can be a way to get to know your neighbors!

Q – I want to partition my hard drive but can’t because there is data spread across the drive. The defragmenter utility in Vista does not move the data to one end of the drive. Has anyone solved this problem or found a utility that works?

A – The recording was too garbled for me to report the suggestions made at the meeting, however both Symantec Partition Magic and Acronis Disk Director Suite will move the data as part of the partitioning process. There is a user group deal on Acronis products are available in the member’s only section of the DACS Community Forum.

Questions for the upcoming meeting can be emailed to askdacs@dacs.org.

Disclaimer: Ask DACS questions come from members by email or from the audience attending the general meeting. Answers are suggestions offered by meeting attendees and represent a general consensus of those responding. DACS offers no warrantee as to the correctness of the answers and anyone following these suggestions or answers does so at their own risk. In other words, we could be totally wrong!