Q: My iMAC is extremely slow, do I have a virus? or just lack of memory?

By the way... OS X 10.7.5 is Lion.

Click Here  >   Why is my computer slow?

Hi vmate, The best way to speed up your computer is to close programs that don't need to be open and allow OS X to run it's maintenance tasks. You shouldn't need Onyx to do that for you. Onyx and programs like that can actually be destructive and causing you problems. I would upgrade to Mountain Lion as well, it's always best to be running the latest software.

One option is to upgrade RAM to 8GB - it will make some difference. Don't expect double the speed as it doesn't work quite like that.

For malware - don't panic about it too much. Get SOPHOS antivirus, and it will take care of most of it. Stay on reputable websites and you'll be fine.

One last thing is to double check that your HDD doesn't qualify for replacement by Apple, or get it checked by a technician.

You're Welcome.

To keep your Mac happy... have a read here...

http://support.apple.com/kb/HT1147

http://www.thexlab.com/faqs/maintainingmacosx.html

Mac OS X: About background maintenance tasks

They should automatically be going - I don't ever need to make mine start.

That's good about your HDD - though I would still get it checked out, I've found more often than not a seriously slow computer is the first sympton of a dying hard drive.

This happened to me.....sounds like your Hardrive has started to fail.

Hi vmate001 –

AnaMusic's links should be very helpful in your case. Did you check your hard drive usage, is there plenty of free HD space available? Do you have a lot of photos or videos – especially in iPhoto which opens all photos together as one large file? With the computer you have, even 4GB RAM should feasibly be okay, 1min to open Safari seems very wrong to me.