Hello!!
I would like to know of some very good antivirus for Windows XP Pro x64, like Norton or McAfee (Including both of these 2).

Norton (2006) and McAfee (2006) aren't good AV at all for two main reasons:

1. They are very heavy on system resources. Both in their GUI (<Screenshot) and processes/services.

Screenshots:
Processes while Idle (just running in the background, not scanning)
Processes after a full system scan
Services

Now compare those with these following screenshots from Kaspersky and NOD32:

Kaspersky

Main GUI
Processes, er, process rather while Idle
After a full system scan

NOD32

Main GUI
Scanning GUI
Scanning Options 1
Scanning Options 2
Processes While Idle
Processes After Full System Scan

Now why have such an unnecessarily massive application installed when a smaller one that takes up much less memory and has a more compact and organized GUI can defend against viruses better?

2. They do have good detection rates, however, are not good at actually removing viruses.

Sure, they have the money to market their products so everyone knows about them, and they may very well be the pioneers of the anti-virus industry that paved the way for future products, but far more efficient products have stepped up to the plate.
Kaspersky and NOD32 are the two very best anti-virus products when taking the following into consideration:
a. GUI
b. Ease of use
c. memory footprint
d. Filesize
e. Features
f. Detection rates

They have both recently, within the last week, come out with final new versions which fully support x64. Try these out, update them, and configure them to their maximum scanning capability. I hope you find satisfaction with one or the other.

For more info on anti-virus, anti-spyware, the current and future threats to PCs, follows the following links for an abundance of info:
http://www.av-comparatives.org
http://www.virusbtn.com

Thank You very much for that information.
What about Symantec AntiVirus Corporate Edition v10.2.199, is this one any good? It doesn't look as heavy as the other Norton antivirus.

As I do not have Vista, I am unable to test the v10.2.199 release.
I can, however, provide information on v10.1.5.5000 for XP x86/x64.

Screenshots:

Processes (Before Scan, Running in the background)
Processes (After full system scan)
Services (Not configured, left as default)
Main GUI
Details of completed scan

Within the program:

Scanning Options
Scanning Options - Advanced
Auto-Protect - Advanced Options
E-Mail Auto-Protect
E-Mail Protect - Advanced Options
Heuristic Scanning Options
Tamper Protection

Pre-installation filesize - 33.4 MB (35,033,088 bytes)
Post-installation filesize - 114 MB (119,566,336 bytes)

the best anti virus to use on any of the windows operating systems is Avast anti virus, it updates every day, picks up every known virus, u can do a dos based scan on boot so it guarentees virus removal, i work for a computer company and we fix 30 systems a day many of witch have virus problems and this removes everything with a boot time scan and seems to even pick up viruses that kapersky, panda, norton, mcaffe, avg and many other progs seem to miss

I like Bitdefender, but no any solution available for Win XP x64 at current.............

not according to many leading testing sites, it doesn't. nothing does.
http://wiki.castlecops.com/AntiVirus_Comparison


It also has the highest "false detection" rate of any antivirus program on the market, free or not. Avast! is not "the best" it is simply "good".

I prefer Symantec corporate or CA's eTrust product, but you'll get all kinds of responses to a question like this.

? I'm interested in performance and reliability, and those two products (believe it or not) work absolutely great on x64 if you use the right versions .

Well, suit yourself but I've tested multiple versions of Symantec, but not the latter, and was not impressed. Kaspersky and NOD32 offer reliability and performance as well, for a fraction of the harddrive space and memory requirements of Symantec.

If you're running an x64 version of Windows and are worried about memory requirements, that seems silly to me. But, to each his or her own - like I said before, this kind of question will get all kinds of responses, with no "right" answer.

I'm not running x64. The reason why memory usage concerns me particularly regarding anti-virus software is, why use a bloated piece of software that installs 100-200 MBs of files on your system and takes up 100 MBs of memory when another program has a higher detection rate, works harder to remove viruses and uses less filesize and memory?
I'm not speaking of exact numbers, just generalizing.

I agree 100%. Norton and Mcafee don't have good detection rates to begin with. There is no point of giving your antivirus that much resources if it is going to be terrible.

I prefer Mcafee Enterprise 8.5 for everything: XP, Server, x64 etc. Works fine for me.

Theoretically speaking a program that is 1KB long is likely to be faster than a program that is 1PB long. Realistically speaking there is a strong correlation between program size and speed. This is probably because the authors that care about their memory usage are the same authors that want their programs to be fast and reliable. The authors that don't care about memory usage are the same ones that buy crashy bloated libraries from any low quality vendor just to add one more unnecessary gewgaw. All the memory in the world can't counteract the poor quality products that result from practices that use too much memory.

Lazy bloatware programming is fine for occasional use programs but there's no place for it with stuff that sits in your system tray particularly when it monitors everything that goes on in the system. Either you're perfect or you're out!

I'm using Avast! Antivirus; I've had an issue with Avast! Antivirus concerning its P2P Shield (slowed down transfers A LOT!) so I disabled it.
I also tried NOD32 but I had too many false alarms so I uninstalled it.
I don't care to mention Symantec products, they're bloatware.