Windows XP keeps freezing up

[Rich]

I am running XP Pro, about a week ago (no new programs added) my
computer would start freezing up sometimes but not always which makes it
even more confusing. Usually but not always it's as I launch a program,
try to exit a program or when I try to exit windows itself..

I try Ctrl + alt+del and something in the background changes (like
behind the frozen program I cannot get out of, I can see my desktop
appear behind the program)....windows task manager MAY appear, if does
at that time it too may lock up. Whenever this 'freeze' occurs I cannot
leave windows, I have to shut off the power. Other times windows task
manager doesn't appear at all.....and yet other times when it will
appear and doesn't lock up, I click the frozen program to "end process"
and then windows itself locks up.
and yet I can launch it now and it works fine.. I have run my updated
anti-virus, done a chkdsk/r, run Spybot and No Adware....nothing is out
of order.
The memory does appear low at times.....
*************************
> OS Name Microsoft Windows XP Professional
> Version 5.1.2600 Service Pack 2 Build 2600
> OS Manufacturer Microsoft Corporation
> System Name SONYNEW
> System Manufacturer Sony Corporation
> System Model PCV-RZ50CG(UC)
> System Type X86-based PC
> Processor x86 Family 15 Model 2 Stepping 9 GenuineIntel ~3191 Mhz
> Processor x86 Family 15 Model 2 Stepping 9 GenuineIntel ~3192 Mhz
> BIOS Version/Date American Megatrends Inc. 1005, 10/1/2004
> SMBIOS Version 2.3
> Windows Directory C:\WINDOWS
> System Directory C:\WINDOWS\system32
> Boot Device \Device\HarddiskVolume2
> Locale United States
> Hardware Abstraction Layer Version = "5.1.2600.2180 (xpsp_sp2_rtm.040803-2158)"
> User Name SONYNEW\Richard
> Time Zone Eastern Daylight Time
> Total Physical Memory 1,024.00 MB
> Available Physical Memory 592.21 MB
> Total Virtual Memory 2.00 GB
> Available Virtual Memory 1.96 GB
> Page File Space 2.41 GB
> Page File C:\pagefile.sys
************************************
> 0xFE800000-0xFE8FFFFF Intel(R) 82865G\PE\P Processor to AGP Controller - 2571 OK
> 0xCFF00000-0xEFEFFFFF Intel(R) 82865G\PE\P Processor to AGP Controller - 2571 OK
> 0xF8000000-0xFBFFFFFF Intel(R) 82865G\PE\P Processor to AGP Controller - 2571 OK
> 0xD0000000-0xDFFFFFFF ATI RADEON 9600 Series OK
> 0xFE8F0000-0xFE8FFFFF ATI RADEON 9600 Series OK
> 0xFE900000-0xFE9FFFFF Intel(R) 82865G\PE\P Processor to PCI to CSA bridge - 2573 OK
> 0xFE9E0000-0xFE9FFFFF Intel(R) PRO/1000 CT Network Connection OK
> 0xFEBFFC00-0xFEBFFFFF Standard Enhanced PCI to USB Host Controller OK
> 0xF0000000-0xF3FFFFFF Sony MPEG RealTime encoder board OK
> 0xFEAFE000-0xFEAFEFFF NEC OHCI Compliant IEEE 1394 Host Controller OK
> 0xFED20000-0xFED8FFFF Motherboard resources OK
> 0xFFB00000-0xFFBFFFFF Motherboard resources OK
> 0xFEC00000-0xFEC00FFF Motherboard resources OK
> 0xFEE00000-0xFEE00FFF Motherboard resources OK
> 0xFFEFFC00-0xFFEFFFFF Intel(R) 82801EB Ultra ATA Storage Controllers OK
> 0x0000-0x9FFFF System board OK
> 0xFFF00000-0xFFFFFFFF System board OK
> 0xA0000-0xBFFFF PCI bus OK
> 0xA0000-0xBFFFF Intel(R) 82865G\PE\P Processor to AGP Controller - 2571 OK
> 0xA0000-0xBFFFF ATI RADEON 9600 Series OK
> 0xC0000-0xDFFFF System board OK
> 0xE0000-0xFFFFF System board OK
> 0x100000-0x3FFFFFFF System board OK
> 0x40000000-0xFFEFFFFF PCI bus OK



Anyone got any ideas?

Rich