Upgrade iMac late 2006

Question

As requested.   Will repeat description of my problem and add one other annoying intrusion.  The Whirling Ball has started to appear (have been working on a newsletter in Pages)  Solution so far is to quit Pages and reopen, not very elegant.
My Mac is 20 inch "late 2006" running 10.7.5 which is apparently it's maximum.  Processor is 2.33 Ghz Intel Core 2 Duo and Memory is 3 GB 667  Mhz DDR2 SDRAM.   (was originally 2 GB, but local Apple shop added 1more last year)
Recently I have had slightly weird problems.. e.g. on start-up it opens with Mac Word, or Excel, neither of which are Log-In items, which are restricted to Mail and Safari.  Other unusual "happenings" are Screen Freezes, (resolved by clicking here and there)  Something called "iWeb" has appeared along the row at the bottom of the screen, and I get asked for my Confidential Information on "Mobile Me" (which I have refused)
               another "aid" attached to each item in the row at the bottom of the screen, is the list of "options"    Was this an upgrade of 10.7.5 somewhere in the last 6 months  ?  
     I have been told I can reload System 10.7.5, and I have thought about (worst scenario ?) buying a new 21" iMac with latest bells and whistles, but I suspect that somehow, Cloud has wormed it's way, uninvited, into the system.
     Is my problem unique ?   If not, do you have a suggestion for a clean-up.
     My Disc Utility says Mac HD 250 GB    Used 166 GB   No. of files  !   645,500  !!      Have two external HD  a. Time Machine   b. Photos, Music, other old stuff.
           Will appreciate suggestions             Eric

Answer 1

Omni Disk Sweeper is a good program/application.
You want to keep that app as it is useful for finding all types of files you may want to keep or delete.
Here are some general tips to keep your Mac's hard drive trim and slim as possible
You should never, EVER let a computer hard drive get completely full, EVER!
With Macs and OS X, you shouldn't let the hard drive get below 15 GBs or less of free data space.
If it does, it's time for some hard drive housecleaning.
Follow some of my tips for cleaning out, deleting and archiving data from your Mac's internal hard drive.
Have you emptied your Mac's Trash icon in the Dock?
If you use iPhoto or Aperture, both have its own trash that needs to be emptied, also.
If you store images in other locations other than iPhoto, then you will have to weed through these to determine what to archive and what to delete.
If you are an iMovie/ Final Cut user, both apps have their own individual Trash location that needs to be emptied, too!
If you use Apple Mail app, Apple Mail also has its own trash area that needs to be emptied, too!
Delete any old or no longer needed emails and/or archive to disc, flash drives or external hard drive, older emails you want to save.
Look through your other Mailboxes and other Mail categories to see If there is other mail you can archive and/or delete.
STAY AWAY FROM DELETING ANY FILES FROM OS X SYSTEM FOLDER!
Look through your Documents folder and delete any type of old useless type files like "Read Me" type files.
Again, archive to disc, flash drives, ext. hard drives or delete any old documents you no longer use or immediately need.
Look in your Applications folder, if you have applications you haven't used in a long time, if the app doesn't have a dedicated uninstaller, then you can simply drag it into the OS X Trash icon. IF the application has an uninstaller app, then use it to completely delete the app from your Mac.
To find other large files, download an app called Omni Disk Sweeper.
http://www.omnigroup.com/more
Also, Find Any File
http://apps.tempel.org/FindAnyFile/
Typically, iTunes and iPhoto libraries are the biggest users of HD space.
move these files/data off of your internal drive to the external hard drive and deleted off of the internal hard drive.
If you have any other large folders of personal data or projects, these should be archived or moved, also, to the optical discs, flash drives or external hard drive and then either archived to disc and/or deleted off your internal hard drive.
Moving iTunes library
http://support.apple.com/kb/HT1449
Moving iPhoto library
http://support.apple.com/kb/PH2506
Moving iMovie projects folder
http://support.apple.com/kb/ph2289
Things to consider before moving your iPhoto Library Folder to a new or external location like an external hard drive.
If you make movies on any iDevices using iMovie for iOS,, then transfer the video footage, the IOS version of iMovie saves the footage as a movie file in IPhoto for IOS and will automatically get transferred to iPhoto for the Mac when you upload the video from your iDevice.
Newer versions of iMovie will work and link those video files found in your iPhoto Library on your Mac, but those links can be lost if you move your iPhoto library and you will not be able to relink that video afterwards as the current versions of iMovie seem to not have a relink option for the video portion of the files (ironically, current versions of iMovie HAVE the ability to re-link the audio files from the video footage, though  (The inability to re-link the video files could be a possible bug or oversight in current versions iMovie).
The lost video links show up as "blacked-out" video blocks with no content.
Before moving the iPhoto Library
If you make movies with iMovie using iPad or iPhone video then 'Consolidate' the files before you finish. This will gather (albeit by duplicating) all the relevant files in the project in one place. After consolidating/duplicating all of the audio and video footage to a seperate, independent location,it should be safe to move your iPhoto library.
The potential way to circumvent this issues maybe to try and import  iPad and iPhoto video directly into iMovie which would be another solution.
FYI,
WHile the max. RAM of your year and model iMac is 3 GBs, Macs typically work better with pairs of matched RAM modules.
If you so choosr, you could replace that 1GB RAM module with another 2 GB RAM module. Your Mac will NOT recognize the complete 4 GBs of total RAM installed, but it will recognize between 3.2 to 3.4 GBs of the total 4 GBs and more important will respond slightly better with matched pairs of RAM.
The difference won't be too dramatic. So, it is up to you if you want to spend the extra money to purchase and install that 2GB RAM module.
Correct, compatible and reliable Mac RAM can ONLY be purchased from online RAM sources Crucial memory or OWC (http://www.macsales.com).
RAM is user installable/upgrade able and is, relatively, easy for newbie or novice Mac users to install.
http://eshop.macsales.com/installvideos/imac_intel_white_mem_h/
Good Luck!