What determines whether the RAM on an i7 mother-board runs as dual- or tri-channel memory? Is there a difference between RAM sticks, or is the only difference in how they are placed in the motherboard slots?

The Dell XPS desktops that have Core i7 can run as dual-channel when they have DIMMs in four slots, with 4GB or 8GB RAM. The same machine can run as tri-channel with DIMMs in three slots for a total of 3GB, or in six slots for a total of 6GB or 12GB (though I don’t know who needs 12GB of RAM.)

Could the same 2GB sticks be used in dual- or tri-channel machines depending only on how they are placed in the slots?

Over the last four months, I have noticed a drastic drop in my computer’s ability to run games. I have Call of Duty 4 and Call of Duty: World at War, both of which ran perfectly at 1400x900 with all settings at max or medium. But when I go to play them now, I experience momentary freezes, which I can “fix” with Ctrl-Alt-Del and then hitting Cancel (32-bit Vista Ultimate). But eventually, while playing the game, there will come a point where it just freezes the entire computer and blue screens. There are also many artifacts within the game, as well as other rendering problems. Now I have to play the games on the absolute lowest settings to delay the inevitable crash, which helps a little. Once rebooted, Vista will report either a fault from my graphics card—an Nvidia 7900 GT—or an unknown error. I have updated all my drivers, defragmented my hard drives, and re-installed the game. What’s going on here?

I have 32-bit Vista installed on my system and have had it since it was released back in ’07. Each day when I start up, I sit and watch the cursor spin and watch the task bar fill. Every time I think it’s ready to go, it loads more programs. Is there some sort of graphical bar or gauge that can be loaded onto the desktop at logon that will show all of my background services loading, so I can tell at a glance whether my computer is actually ready to go? Windows 7 beta still offers NO progress bar/gauge to indicate when all background services are finished loading. I have used Sabayon Linux in the past and it did have a progress bar before the desktop had even appeared. This has really been a pain in my “mouse click,” so if you can help with this I would really appreciate it.

Read on to see the answer to Ray's question.

I have a problem booting from my Windows XP installation disc. When I installed Windows XP for the first time, I didn’t have any problems. I could see “press any button to boot from CD,” and pressing the button would start the installation process. As soon as Windows XP is installed, I reboot and I see “press any button to start from CD,” but nothing happens when I press a button, and it loads Windows from the hard drive, not the installation CD. It looks like the keyboard isn’t recognized.

I have a Gigabyte GA-K8NXP-SLI motherboard and a Sapphire Radeon HD 4850 videocard. My processor is an AMD 64 X2 4800.

See the solution to Vitaliy's problem after the jump.