Thanks very much for your reply Barney. I have run EtreCheck and will proceed to try to do what it says, but would be grateful for any further advice. As you can probably tell, I am not great at technical computer problems . I've attached my results. Thanks again.
EtreCheck version: 2.9.7 (257)
Report generated 2016-02-27 12:35:04
Download EtreCheck from http://etrecheck.com
Runtime 3:42
Performance: Good
Click the [Support] links for help with non-Apple products.
Click the [Details] links for more information about that line.
Click the [Remove] links to remove adware.
Problem: Computer is too slow
Hardware Information: ⓘ
iMac (20-inch, Early 2008)
[Technical Specifications] - [User Guide] - [Warranty & Service]
iMac - model: iMac8,1
1 2.4 GHz Intel Core 2 Duo CPU: 2-core
4 GB RAM Upgradeable - [Instructions]
BANK 0/DIMM0
2 GB DDR2 SDRAM 800 MHz ok
BANK 1/DIMM1
2 GB DDR2 SDRAM 800 MHz ok
Bluetooth: Old - Handoff/Airdrop2 not supported
Wireless: en1: 802.11 a/b/g/n
Video Information: ⓘ
ATI Radeon HD 2400 - VRAM: 128 MB
iMac 1680 x 1050
System Software: ⓘ
OS X El Capitan 10.11.3 (15D21) - Time since boot: about 2 hours
Disk Information: ⓘ
Hitachi HDP725025GLA380 disk0 : (250.06 GB) (Rotational)
EFI (disk0s1) <not mounted> : 210 MB
Macintosh HD (disk0s2) / : 249.20 GB (167.17 GB free)
Recovery HD (disk0s3) <not mounted> [Recovery]: 650 MB
USB Information: ⓘ
SEIKO EPSON USB MFP
Apple Inc. BRCM2046 Hub
Apple Inc. Bluetooth USB Host Controller
Apple Computer, Inc. IR Receiver
Apple, Inc. Keyboard Hub
Mitsumi Electric Apple Optical USB Mouse
Apple, Inc Apple Keyboard
Apple Inc. Built-in iSight
Configuration files: ⓘ
/etc/sudoers, File size 1242 but expected 2299
Gatekeeper: ⓘ
Mac App Store and identified developers
Adware: ⓘ
~/Library/Application Support/com.genieoinnovation.Installer
One adware file found. [Remove]
Kernel Extensions: ⓘ
/Applications/Toast 9 Titanium/Toast Titanium.app
[not loaded] com.elgato.driver.Pluto2 (1.1 - 2014-07-27) [Support]
[not loaded] com.roxio.BluRaySupport (1.1.6 - 2014-07-27) [Support]
[not loaded] com.roxio.TDIXController (1.7 - 2014-07-27) [Support]
/System/Library/Extensions
[not loaded] com.devguru.driver.SamsungComposite (1.4.37 - SDK 10.6 - 2016-02-05) [Support]
/System/Library/Extensions/ssuddrv.kext/Contents/PlugIns
[not loaded] com.devguru.driver.SamsungACMControl (1.4.37 - SDK 10.6 - 2015-12-15) [Support]
[not loaded] com.devguru.driver.SamsungACMData (1.4.37 - SDK 10.6 - 2015-12-15) [Support]
[not loaded] com.devguru.driver.SamsungMTP (1.4.37 - SDK 10.5 - 2015-12-15) [Support]
[not loaded] com.devguru.driver.SamsungSerial (1.4.37 - SDK 10.6 - 2015-12-15) [Support]
System Launch Agents: ⓘ
[not loaded] 7 Apple tasks
[loaded] 159 Apple tasks
[running] 70 Apple tasks
System Launch Daemons: ⓘ
[not loaded] 46 Apple tasks
[loaded] 159 Apple tasks
[running] 82 Apple tasks
Launch Agents: ⓘ
[running] com.epson.epw.agent.plist (2008-03-28) [Support]
[loaded] com.google.keystone.agent.plist (2015-12-16) [Support]
Launch Daemons: ⓘ
[loaded] com.adobe.fpsaud.plist (2016-01-29) [Support]
[loaded] com.google.keystone.daemon.plist (2015-12-16) [Support]
[loaded] com.securemac.MacScanDaemon.plist (2016-02-23) [Support]
User Launch Agents: ⓘ
[loaded] com.adobe.ARM.[...].plist (2012-09-23) [Support]
[failed] com.zeobit.MacKeeper.Helper.plist (2012-11-02) [Support]
User Login Items: ⓘ
Secure Mac Cleaner Application (/Applications/Secure Mac Cleaner.app)
Dropbox Folder (~/Dropbox)
Google Chrome Application (/Applications/Google Chrome.app)
fuspredownloader Application Hidden (~/Library/Application Support/.FUS/fuspredownloader.app)
KiesAgent Application Hidden (/Applications/Kies.app/Contents/MacOS/KiesAgent.app)
Other Apps: ⓘ
[loaded] com.google.Chrome.59232
[running] com.microsoft.autoupdate.fba.113632
[running] com.microsoft.entourage.database_daemon.6432
[running] com.yourcompany.KiesAgent.92832
[running] jp.co.canon.cijscannerregister.87072
[loaded] 410 Apple tasks
[running] 175 Apple tasks
Internet Plug-ins: ⓘ
o1dbrowserplugin: 5.41.3.0 - SDK 10.8 (2016-01-23) [Support]
Google Earth Web Plug-in: 7.1 (2013-10-07) [Support]
Default Browser: 601 - SDK 10.11 (2016-01-14)
AdobePDFViewerNPAPI: 11.0.14 - SDK 10.6 (2016-02-16) [Support]
FlashPlayer-10.6: 20.0.0.306 - SDK 10.6 (2016-02-10) [Support]
AmazonMP3DownloaderPlugin101749: AmazonMP3DownloaderPlugin 1.0.17 - SDK 10.4 (2013-06-04) [Support]
Silverlight: 5.1.20913.0 - SDK 10.6 (2013-12-21) [Support]
QuickTime Plugin: 7.7.3 (2016-01-14)
Flash Player: 20.0.0.306 - SDK 10.6 (2016-02-10) [Support]
googletalkbrowserplugin: 5.41.3.0 - SDK 10.8 (2015-12-11) [Support]
iPhotoPhotocast: 7.0 (2009-06-02)
AdobePDFViewer: 11.0.14 - SDK 10.6 (2016-02-16) [Support]
JavaAppletPlugin: 15.0.1 - SDK 10.7 (2013-05-08) Check version
Safari Extensions: ⓘ
Facebook Photo Zoom (2012-08-28)
Add To Amazon Wish List (2013-11-11)
3rd Party Preference Panes: ⓘ
Flash Player (2016-01-29) [Support]
Time Machine: ⓘ
Time Machine not configured!
Top Processes by CPU: ⓘ
2% WindowServer
1% kernel_task
0% fontd
0% Google Chrome
0% Skype
Top Processes by Memory: ⓘ
926 MB Google Chrome Helper(7)
413 MB kernel_task
348 MB Photos
254 MB Google Chrome
139 MB mdworker(8)
Virtual Memory Information: ⓘ
105 MB Free RAM
3.90 GB Used RAM (1.09 GB Cached)
768 KB Swap Used
Diagnostics Information: ⓘ
Feb 27, 2016, 10:10:12 AM /Library/Logs/DiagnosticReports/Secure Mac Cleaner_2016-02-27-101012_[redacted].hang
/Applications/Secure Mac Cleaner.app/Contents/MacOS/Secure Mac Cleaner
Feb 27, 2016, 10:02:18 AM Self test - passed
Feb 25, 2016, 01:00:09 PM ~/Library/Logs/DiagnosticReports/Kies_2016-02-25-130009_[redacted].crash
com.samsung.Kies - /Applications/Kies.app/Contents/MacOS/Kies
Feb 24, 2016, 07:28:51 PM ~/Library/Logs/DiagnosticReports/MassStorageCamera_2016-02-24-192851_[redacted] .crash
com.apple.MassStorageCamera - /System/Library/Image Capture/Devices/MassStorageCamera.app/Contents/MacOS/MassStorageCamera
Feb 24, 2016, 07:02:25 PM ~/Library/Logs/DiagnosticReports/MassStorageCamera_2016-02-24-190225_[redacted] .crash