Annoying startup lag + weird sound

[diamond0099]

Hi!
I'd first like to note that this is connected with my previous thread about being stuck in classic mode.
I don't remember when this started happening, but it was probably around March.
One day, after starting up my PC, I noticed that the login screen was black. I tried restarting it a few times after waiting a bit, but it would still be black, so I looked it up on my tablet. As I was looking around forum threads with people having the same problem as me, I noticed the login screen appeared. I don't think the sound started here yet.
Now, every single time I start up my computer, the login screen is black for a few minutes and during that the PC makes a clicking sort of sound. I can't really describe it, but if needed I can try and provide a recording. After it appears, when I log on, it will start making the noise a few more times. While the computer is making the clicking sound, it freezes up and I can't do anything. It then stops and everything is perfectly fine until I close it and start it up again. I am posting this not because i'm worried about the problem but more because i'm annoyed by the freeze-ups.
I can provide system specs if needed.
Thanks!
EDIT - Sorry, but I forgot to provide some details.
When the problem first started, sometimes the computer would start in classic mode and I wouldn't be able to change it back to Aero. It would also turn off by itself sometimes. However, now it always starts in Aero and it doesn't turn off by itself.
After starting up, audio will be usually disabled. I don't mean muted, I mean disabled. The volume icon will have a red circle with a white cross on it and I will have to click it so that it will go into "Detecting problems" and enable it back again.
If I start Firefox while the audio is disabled and I try to view a YouTube video, even after multiple refreshes it will say that a error has occured. If the audio is enabled back, it doesn't fix it. I have to close and open Firefox again.

 

[ICIT2LOL]

Hiyya Diamond mate the sounds to me this smacks of the hard drive going south especially the clicking sounds and the strange behaviour it may be worth a test on it so try this even if you have to hook it to another machine.
SeaTools for Windows | Seagate

A few more specs would be good too please http://www.sevenforums.com/tutorials/180324-system-info-see-your-system-specs.html

 

[diamond0099]

Specs:
Home Premium x64 Service Pack 1
Processor: Intel Core 2 Quad CPU Q6600 2.40 GHz
4 GB of RAM

I don't have any data backups and I have tons of games etc. on there so i'm a bit worried about doing a fix right now. Out of the "Basic Tests" which one do I do first?

 

[Keager]

if you have a large external HDD, I would download a disk copier (I've used Macrium Reflect) and get it copied if the HDD is failing.

 

[diamond0099]

Well, I have 2 HDDs and they are quite large... C:\ - 146 GB, D:\ - 319 GB. I'll try doing that later today, thanks.

 

[mitchell65]

Well, I have 2 HDDs and they are quite large... C:\ - 146 GB, D:\ - 319 GB. I'll try doing that later today, thanks.

But your two drives appear to be installed in your PC and the suggestion was to use an external hard drive for a backup. Both your drives are quite small by today's standards!

 

[ICIT2LOL]

Yep and again for my two cents worth I would e doing a clone instead of just a back up if the drive is going south then it would be easy to clone back to a new internal drive.

Just a by the by have you run that Seatools yet just to eliminate if the drive is the problem??