Multiple problems with Pc and dust, random startups & poor performance

[bomberswarm2]

Multiple problems with Pc and dust, random startups & poor performance

I have several questions to ask about my current computer.

My PC specs are at the end of this list.

1. My computer sometimes won't come out of standby

When I take my computer out of sleep mode in the morning, half the time it will not work. One of two things happens:
a) The computer will start, but the screen will stay blank
b) The computer will start, the screen will flash between being on, but blank, and going off, and displaying 'no source detected'.
Is there any way to fix this?

2. My power supply makes a terrible noise when bringing the computer out of standby, and rarely when starting it up.

The power supply makes a grinding noise. I wasn't sure what was causing it for a while, but I knew it was a fan. I took it out of standby one day, and stopped each fan moving with a pen, and when I stopped the fan inside my PSU, the noise stopped.
Is this a sign that I need a new PSU? Could this lead to other problems?

3. How badly is this dust affecting my computer's performance?

Here are some photos of inside of my computer.

Imgur: The most awesome images on the Internet

How much is this dust going to effect my performance, in relation to the parts listed below?
How do I clean this dust out of my computer without damaging all the components?
My computer's preformance is pretty poor. It constantly lags while doing simple tasks, such as opening an instance of a program for the first time after startup (as in after I take it out of standby, the first time I start Google Chrome or any program, it will take a really long time to open, and when it finally does, it will lag on entering text into the adress bar, or when I click on a shortcut, but after this first time, it won't lag again).
For an example of the preformance, I can only run Trainz Simulator 2012 in the lowest settings with incredible lag and atrocious frame rate. The minimum specs are here: Trainz Simulator 12 Requirements
As another example, my computer struggles to run Cities Skylines as my population reaches 10,000 people. Many other players report similar experiences at 100,000-200,000 people. The recomended specs for that are here: Cities: Skylines System Requirements | Can I Run Cities: Skylines PC requirements

Those are just two examples of poor performance. Is this because of the dust, or because of my hardware?

4. Computer turning on at 3am every second day

About every second or third day, I will either wake up and find my computer on, or be awake in bed, and hear it start back up. I can find no reason for it to do this. I have turned off all Microsoft scheduled programs. What can I do to fix this?

5. Computer parts

I am looking to upgrade my computer over the next few months. I was going to do it all at once, but I would now prefer to do it over time so I can get new parts sooner rather than wait several more months.
I will upgrade my CPU to an Intel i5 processor, a new graphics card and buy more ram. What else from the parts below should I upgrade? Any suggestions for parts? What would be the priority ordering if buying over time? Would their be any disadvantages to me upgrading over time, or any advantages to me upgrading all at the same time?

Thanks for your help.

System Specs:

System Manufacturer Gigabyte Technology Co., Ltd.
System Model GA-880GM-USB3
System Type x64-based PC
Processor AMD Phenom(tm) II X4 955 Processor, 3200 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date Award Software International, Inc. F8, 15/10/2010
SMBIOS Version 2.4
Hardware Abstraction Layer Version = "6.1.7601.17514"
Installed Physical Memory (RAM) 4.00 GB
Total Physical Memory 4.00 GB
Available Physical Memory 2.25 GB
Total Virtual Memory 11.7 GB
Available Virtual Memory 8.41 GB

Hard Drives:
Internal:
C - Main, 2Tb, 1.3Tb free
E - Storage, 500Gb, 20Gb free
F: - Storage, 1Tb, 0.25Tb free

External:
G: 1Tb, 20MB free
H: 3Tb, 2.2Tb free

 

[ThrashZone]

Hi,
Yes by all means clean out the machine,
The cpu cooler/ heat sink is caked with dust build up only way to clean it is to disassemble it = remove the fan.
So is the exhaust fan
It's pretty bad.

I'm sure the power supply is pretty bad too it pulls air from the inside of the case and pushes it out.
Not too may ways to clean it besides blowing a lot of clear air through it from both directions :/

 

[Mellon Head]

Yes, clean the machine.

But do NOT, under any circumstances, use a vacuum to do it. You'll kill your hardware.

 

[bomberswarm2]

How do i do it then?

 

[ThrashZone]

Hi,
Compressed air cans or if you have a compressor for that much filth
Just make sure the compressor isn't blowing any water.