Win 7 Randomly Freezing / Crashing

When I boot up my pc, randomly 15-30minutes after logging on, all of the programs running will freeze with "Not Responding" on their title bar for a few minutes. After a few minutes the programs will unfreeze, and more problems arise.

These problems include, some of the open programs working, some partially working , and some not working at all. When I try to to ctrl alt delete to close the frozen programs, an error message will pop-up Cannot find explorer.exe. Also when I open the start menu it is completely blank, doesn't show anything. Also, some of my desktop icons disappear, while some others stay. In general, the computer gets really buggy, and I cant do much.

I have been having these issues for roughly a week. I formatted on Mon, Aug 27, and the issues still arise since the format, so it appears the issues is more likely hardware related.

Since I formatted, I have chkdisk /f /r, and sfc /scannow, but the issues still arise.

About a week ago I was trying to clean my case, get rid of dust, etc, but before I did it, my case fell roughly 6 inches to the ground, thinking this issue could be hardware, most likely a bad HDD related.

Any tips or hints? Thanks

Also I just found about 15 criticial entries in my Event Viewer

The driver detected a controller error on \Device\Harddisk1\DR1. and The device, \Device\Harddisk1\DR1, has a bad block.

But all of these entries occur within a 5 minute time period, it could explain one crash, but not all of them.

So more evidence its a HDD issue.

Also found another event happening ALOT

A corrected hardware error has occurred.

Component: PCI Express Root Port
Error Source: Advanced Error Reporting (PCI Express)

Bus: Device:Function: 0x0:0x0:0x0
Vendor ID: Device ID: 0x8086:0x3405
Class Code: 0x30000

The details view of this entry contains further information.

It crashed again, I got 3 error box's that came up, I took a picture of them with my phone.

I was trying to uninstall bing bar from ie, with event viewer open to see when / if any errors came up.