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BYTEBACK
Facts about PC power supplies
This refers to the article “Understand what ‘pure power’ means to PC” by Saad Bin Riaz (June 19 edition). As a professional in this field, I am fully aware of the technicalities involved in the manufacture of a high-quality power supply and would like to discuss them with your esteemed readers. Mr Riaz, on the other hand, has not even touched upon the fundamentals of choosing one and has instead gone ahead with utterly non-sensical statements such as “cheap PSUs trying to act as a fouls play.” Instead following should have been discussed:
1. The mean time between failure
2. The hold-up time
3. The Peak Inrush Current
4. Transient Reponse
Other essential “facts” that should have been mentioned include: an explanation of overvoltage protection, the maximum and minimum load current, voltage load and line regulation as well as the power factor correction. The latter has now become a major topic of discussion due to the stringent standards enforced by the European Union countries pertaining to the reduction of harmonics. To my surprise, this has not even been mentioned, let alone discussed at length. If the article was supposed to be general, why touch upon “rails” in the first place?
Other than this, the writer, clearly dwelling in his own fantasy, has suggested the +12V rail for use by a motherboard. Reality is this: in most modern PCs, this is primarily used to power disk drive motors and other cooling devices as well as system bus slots, instead of the motherboard. Furthermore, Mr. Riaz has also mis-stated the functions performed by the +5V rail, which serves the motherboard and other components.
Later, the writer goes on to suggest modding of cheap Chinese power supplies by “cutting a large hole on the opposite side...and adding another cooling fan.” This is not only ridiculous but extremely dangerous too. The metal case on a power supply is specifically designed for shielding purposes. One can easily get a nasty shock while attempting to remove it by touching a part of the exposed power supply.
In conclusion, I would like to state that the article would have been much, much better had it incorporated these intrinsic facts. I seriously feel that the writer must exercise greater care in choosing a topic before attempting to write on it. Not only will this save him humiliation, but it will also serve as a warning to others and prevent them from taking up issues where they have no knowledge whatsoever.
OMAIR KHAN
University Of California-Berkeley
Email storage rat race
Last week Yahoo! unveiled its new enhanced free email service offering a 100MB of storage, 25 times more than the prior free offering. This is indeed a pleasant change as now you can store all your important documents and messages in your mailbox without worrying about getting out of space.
Apparently the decision has come in response to the announcement made by the rival group, Google, who plans to start a free email service Gmail, featuring a mailbox of 1GB! However, Gmail is still in beta testing and facing strong criticism from privacy groups because Google plans to serve relevant ads in mail messages by scanning their text for keywords. Lycos Europe has also upped the stakes in the email-storage race by offering its own 1GB email service. Spymac.com is already offering a free email acount of 1GB. This is not all that surprising considering that the price of storage has gone down over the past few years, but the average mailbox size stayed relatively unchanged. The competition between Yahoo and Google will also force other mail providers to offer more services. Hotmail, which is arguably the largest email provider, is still giving away a mere 2MB to its users.
Apart from the increased storage and a changed look new features in Yahoo mail include an attachment limit of 10MB for free accounts and address auto-complete. A new improved and powerful search feature has also been incorporated in the mailbox, which will come in handy because of the increased storage capacity. Yahoo has also consolidated all of its premium email services into a single program, called Yahoo Mail Plus, which offers 2GB of storage and lowering its subscription rate from $29.99 a year to $19.99.
MUHAMMAD YASSER SULTAN
NUST, Rawalpindi
Startup error
When I start my PC it gives some “sys.reg error.” How can I get rid of it? Also tell me how can I make DVDs run on my system. At present, my CD-Rom fail to run any, why?
MURTAZA MURAD
Rawalpindi
Editor’s reply: Sys.reg is a malware, which can be a little tricky to remove since it carries variants. In most cases it works as a browser helper object (BHO) and tampers with homepage of your Internet Explorer by creating some dll file. Thus, removing sys.reg from startup and deleting it would not fix the problem as it would just recreate next time Internet Explorer is started. The BHO must be removed first, which can be done with a utility such as hijackthis
If the aforementioned solution doesn’t work, try alternative manual way to delete it from registry. Type Regedit at Run, go to: [HKEY_LOCAL_MACHINE\ Software\Microsoft\Windows\CurrentVersion\Run]
“sys”=”regedit /s sys.reg”
When you find it just delete it. In this way windows will not search sys. reg file anymore and all will work well. Regarding your second question, you require a DVD-ROM drive to run DVDs. They don’t run on normal CD-Roms.
Recovering password
Can logon password be bypassed in Windows OS? Is there any other secure password?
KAMRAN SHAH
Nawabshah
Editor’s reply: It is very hard to bypass a logon password but if you want you can add a boot password. By setting a boot password, you can make your computer prompt for the password every time it is restarted. You can set the boot password in the BIOS when your computer is starting up. Usually the computer tells you when you can enter the BIOS (press Del to enter setup). The BIOS is different for different computers. If you check the documentation for your computer, it should tell you how to set a password. Or, if you feel comfortable exploring your BIOS, simply enter setup and look for a security or boot option.
