Windows 7 Freezes – Disk I/O Light Stays On During Hangs

Just recently, my Windows 7 computer (Thinkpad T410s) is suddenly doing a lot more disk I/O (as indicated by a light on the case) and randomly freezes for a couple seconds at a time before resuming whatever I was doing. The disk I/O light on my laptop stays solid on while the computer hangs (not flickering, like usual).

• I have run a CHKDSK on both my drives, no problems.
• Did a full scan with Microsoft Security Essentials, no viruses
• Checked the ram with Window's built in memory checker (forget the name), no warnings
• Did a full test on hardware with Lenovo's ThinkVantage hardware test software, no issues
• Checked the event log, nothing stuck out as out of the ordinary
• Updated all the drivers (and bios) to the latest version
• Emptied disks so they are less than 50% full
• Did a factory reset of the system, problem still exists
• Cannot reproduce problem in safe-mode <– problem now exists in safe-mode

This is especially weird, since after the factory reset, the problem still exists. I was wondering if anybody has any insight as to what this might be; I'm stumped.

Many thanks for your time.