A couple of things I would try;
Boot back into safemode and perform a “sfc /scannow”. (Can be started from the “run” box of windows 7)
To See and Read the SFC /SCANNOW Scan Results
Allow the computer to boot normally after the scan.

Perform a system & registry cleanup with CCleaner, download it here.
Perform a thorough defragmentation with a tool of your choice or the default Windows 7 defragger;
Open the Start Menu, then type dfrgui into the search line and press Enter.

I was running Chrome with quite few tabs open (17-25) on an ASUS Laptop. And then everything just stopped responding. I tried restarting the pc and was stuck at the “welcome” part of logging on for 1h+ before shutting it off and starting i safemode. It actually logs in, but when i click start it takes 1-2 minutes for the start window to pop up and when i click on anything in there (in safe mode mind you) it takes 5-10 min before it opens control panel or anything else. I dont know whats wrong.

I’m running Firefox v16.0.1 and I’m having exactly the same symptoms. In my case, this problem seems to have started immediately after I had installed the latest MS Windows updates. I’m now thinking of uninstalling them.

A couple of ideas, just things to check:

Have you done a scan for malicious software, for example with http://www.malwarebytes.org ?

Have you checked that the fans are rotating and the airways free of dust?

I would also do a complete cleanup of your PC. Delete temp files, temp internet files, etc. You can use an app such as CCleaner for this chore. See if this helps any.

John might have hit on a great idea. Perhaps a thorough physical cleaning would solve some problems. This could be a heat buildup because of contamination. You might find a lot of contamination inside the PC.

The virus idea is also a distinct possibility.

I’d uninstall whichever Windows updates got installed on the day the problem started. If that doesn’t fix it, uninstall the new external wireless adapter, or see if there’s an update for it.

Have you tried to find out what is happening on your computer. Almost certainly you have a program running in the background which is taking up CPU cycles. open Task manager (Right click a blank space in the toolbar to do this), then select the Processes tab, click on the word CPU at the top of a column – may need to be clicked twice)

When you have it sorting most used first scroll to the top – if necessary. Then you will see what programs are running and what is taking the most cpu cycles. If the “Idle time” is not at the top most of the time then whatever is at the top most often is probably causing the problem. You may be able to disable it or remove it if it is malware.

This is just a start to identifying the problem. Sometimes you need to use something like Sysinternals process explorer to get more info on what is happening.

Let us know what results you get. A screen dump (alt PrtScn and paste into an image file, save, and attach to your response) might help to analyse your problem.

I was running Chrome with quite few tabs open (17-25) on an ASUS Laptop.
…
Thank you so much for you time and consideration.

Do you use Google Chrome?
https://productforums.google.com/forum/?fromgroups=#!topic/chrome/y9SuHg6VTww

Hi,

download Microsoft free FixIt and run it’s features! I am sure that will do.

Under Chrome’s Settings tab, go to Advanced Setting, uncheck the “Continue running background apps when Google Chrome is closed”, if it is checked. Being checked, it continues ALL of your background Chrome extensions, etc. after you leave Chrome.

Hi Kaieil:

I agree with rholmes about heat. I have recently sorted an 8 year old HP laptop that was running really slow after quarter of an hour from start. A clue is fans running continally at high speed. I ended up stripping it down (get hold of a manual if you can, as it is not always obvious how things come apart). There was dust in both fans and fluff in one of the fans.

When I got down to the fan and heatsink assembly, I found that it was glued to the CPU, by the dried out heatsink grease. In fact the CPU pulled out of the ZIF socket, and had to be levered off the heatsink. A cleaning and grease kit did the job – from the local electronics shop. The laptop is now running at a normal speed. Oh – and get a wrist grounding strap.

Hope this helps, windyrij

Unfortunately Eric, that happens regularly. Many add suggestions and nary a peep from the original OP to let us know if the problem is fixed.

We would need a lot more info on your PC, specs, version of Win 7, etc.

How long has it been since you did any maintenance on the PC, cleaned up temp files, cleaned out all the non-essentials startup apps in Windows. How long since AV/AM scans? What AV/AM apps do you use.

Many slow downs such as this are malware and virus related.

Hi, I’ve just had the same thing happen, I realise this is an old thread now, but help would be appreciated as I need my laptop for uni studies, it’s a Lenovo T400 ThinkPad

hi, just got my laptop back from the repair shop, it was a mixture between a faulty hard drive, loose SATA connection and malware, hopefully this helps anyone that has the same issue diagnose what may be wrong with their machine

Glad you got it resolved. Thanks for posting back.

Joe