Windows 7 gets slow even after formatting.

Ok, I got quite a big problem that's been going on for quite a lot of time now (more than one year probably). My PC looks fine for like 1 hour of formatting, after that, it gets slow "in the same way".

Like it will lag a bit when I open a program (or switch between programs), it will get real slow when I boot it (around 3 mins with just avast internet security launching during start-up).

Another slow happens when I launch outlook.com to check my mails, it will 'load' for like 10 seconds after the page has actually loaded before I can start checking my e-mails, and this is not an internet speed problem, the page loads, but seems to kind of be getting ready to load the e-mails, which doesn't happen in that 1 first hour after I've formatted my PC.
Then, when there are flash contents in my firefox, firefox gets totally slow.

Another big problem is multi-tasking. If I'm installing something, it will be almost impossible to do something else.

I installed ubuntu a couple of months ago, and I only kept it for a week, but it never got slow, while with windows 7 it gets slow almost immediately. Now I could try to test dual-booting with XP to see if XP will get slow or not, because honestly I'm clueless as to what could the problem actually be.

During hard work, my (CPU I think) will make this 'grgrgrgrgrgrgr' noise which makes it look really stressed.

I would like to say that my pc is 'a bit' old (bought it almost 4 years ago), but when I first bought it, none of these problems happened, and I used windows 7 back then, so maybe it is from old age.

Bottom line, anyone got any ideas or suggestions to try, I'm out of ideas and I don't think it's normal for a PC to be that slow, given that it was not like that when I first bought it.
I'm posting a SS below with how my CPU is working during an installation and my PC basic hardware info.

The CPU doesn't make any noise because there are no moving parts in it. Well, the heatsink has a fan on it, but the sound you're hearing is likely the normal sounds of a hard drive.

I know that Ubuntu was working just fine, but it sounds to me like there could be something wrong with the hard drive (perhaps it's beginning to show its age and is beginning to die).

I guess it could also be driver-related, but that doesn't result in gradual slow-downs; it results in being slower than normal from the beginning.

My biggest fear is that my HDD is dying, the CPU Cooler should have no problem as I replaced it just a couple of months ago.

@bobafetthotmail
Yes, by formatting I mean real formatting, because at first I thought this could be caused by viruses, so I formatted many times in my desperate attempts to get my PC faster, but to no avail. I've partitioned my HDD, so I keep all my documents and projects in the other logical drive (D:) so I don't lose anything when I format.

Anyway, do you guys think there's any way of understanding if my HDD is dying, if I take it to a service store, can they find that out, because anything related to software I can probably do myself, but checking how HW is doing is not really my thing.

Hmm, I've tried check-disk and the results came out fine on both of my drives

Work through these steps for Troubleshooting Steps for Windows 7 which give you more information on testing the HD completely, checking for overheating, cleaning out the PC if needed, reading logs, establishing a Clean Boot, etc.

In addition compare the reinstall you did to the steps to get a perfect Clean Reinstall - Factory OEM Windows 7