Speeding up my Acer laptop

[DancingHat]

It's been running painfully slowly for months so I've been using the ipad but now I need to use the laptop as a laptop and it's driving me insane with the lag. If I type into Google search it lags showing the word for 5-10 seconds. When opening a browsing window it takes such a long time to open whether it's Chrome, Firefox or Explorer. Things I've tried:
Virus checker AVG free
Spybot - spy ware
Defragmenter
Start up programs - removed via MS config

What else can I do??

I'm currently getting a Windows update message suggesting I get a Windows 10 upgrade. Is this a good idea? I know that if I don't change something nothing will change and I'll get more and more frustrated. It's an Acer Aspire 5742 bought December 2011. Cheers!

Have you tried reinstalling the OS? I'd also consider a memory upgrade and/or replacing the HD with an SSD

If it's slow running previous versions of Windoze it'll collapse in a wheezing heap when you feed it Windoze 10. If you want to give a new lease of life to a modest or slightly old PC, hose the hard drive and install any of the friendlier versions of Linux - Ubuntu is the easiest and everything is free.

Your PC sounds pretty similar to mine and of similar age. I installed Ubuntu the minute it came out of the box. There was a slip with it that said the first time you started Windoze it would take maybe 60 minutes to get out of bed. In that time I'd formatted the drive to ext4, installed Ubuntu, started it, installed half a dozen applications and set up my network.

If I type into a Google search and hit return the results come up in something like half a second. Windoze is shite and with each new version it gets worse. I particularly hate the way it starts churning the hard drive doing God knows what and refusing to respond to you for minutes at a time.