windows 7 becomes unberable slow, what could I do? [duplicate]

31 minutes to boot, you definitely have a problem! You appear to have enough RAM and CPU to work comfortably.

When my computer gets unbearably slow and I see very low CPU usage the culprit will always be disk drive usage. I suggest you start the Resource Monitor and click the Disk tab. You are probably going to see a lot of activity. The reason could be a misbehaving program, or a bad disk.

"Slow" is of course a relative term.

Running Windows 7, I recommend uninstalling everything McAfee and going with Windows Defender and Microsoft Security Essentials (free for Win7 users). That's going to be the highest overhead on your input/output operations (such as writing to disk).

Speaking of writing to disk, the single biggest upgrade you can make for your computer is to get a Solid State Drive (SSD) to contain your operating system and most-used files. For Windows, a 128GB SSD is usually great for that purpose. Just reinstall your operating system and all your files on the drive once you get it hooked up and installed. Here's a video.

You can re-use the Windows license that came with your computer for the new installation, and once you're sure everything is working, you can delete the old installation files. As for where to put the old hard drive, well, you can get a hard drive bay to replace the DVD drive you may or may not be using, or you can go with an external hard drive enclosure kit.

Short of following those suggestions, though, just make sure that your drive is frequently optimized and that you're not running out of storage space (File Exporer => Right Click the drive => Properties to find information about both of these).

Hope this helps.