Computer will start display boot screen and freeze

anyone know what would cause this? Computer will start, display boot screen, and freeze. However after it would freeze on boot option display if i restart the computer again it will boot like nothing ever happened.

note this usally only happens if my computer has been off for a day or two.... saddly it's becoming apparent the problem is getting worse. somtimes it will take my computer about 25sec's of holding the power botton to turn of the computer now. When this first started all i had to do was push the power botton once for 1.5sec's and it would power down.

System Info
OS Name Microsoft Windows 7 Ultimate
Version 6.1.7601 Service Pack 1 Build 7601
Processor AMD Athlon(tm) II X4 640 Processor, 3013 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date Phoenix Technologies, LTD ASUS M2N-E ACPI BIOS Revision 5001, 3/23/2010
SMBIOS Version 2.4
Boot Device \Device\HarddiskVolume1
Installed Physical Memory (RAM) 8.00 GB
Total Physical Memory 8.00 GB
Available Physical Memory 5.31 GB
Total Virtual Memory 16.0 GB
Available Virtual Memory 12.7 GB
Page File Space 8.00 GB

hdd's,
Model ST316081 2AS SCSI Disk Device
Model ST340062 0AS SCSI Disk Device

GPU,
Nvidia GeForce 560 Ti

Network adapter
802.11n Wirless LAN Card

PSU,
I don't know anything other than it's 430watt's........ lol don't ask me how it's running to beggin with because i know the graphics card needs 500wat's in itself. but my computer has been running fine for a year and a half just fine but leaning further into the second year it's starting to fight with me. I'm not sorry if it's time to upgrade "it's done better then anyone who know's about computer told me it would". untill recently when the porblem starting happening the cpu was even overclocked 3% not much but made all the more diffrence. Even though i was only running a 430wat psu with everything i was still playing fortnight at 100fps intill i turned off the overclock now im playing at 60fps witch to be honest makes no sense to me it again was only 3%.

cpuid info...
CPU VCORE Min:1.216, Max:1.248
+3.3 Min:3.136, Max:3.136
+5V Min:4.731, Max:4.758
+12V Min:11.264, Max:11.392
+5V VCCH Min:4.596, Max:4.623
+3.3V Min:3.268, Max:3.320

CPU POWERS/ TEMPS
Min:104.50, Max:104.50
Min:28c, Max:48c

GPU TEMP's under full gaming load

Min:79c, Max:89c