Slow Computer, after 3 months of non use

So finally after 3 months of trying to fix my PC today I hit the jackpot! my PC has now booted up!!

*See my profile for specs*

See now i have booted it up, everything is very slow! my system is quite up to date but now Internet and basic programs are very slow!

any remedies?

CCleaner has been used also*****

Reinstall the OS.

maybe your hard drive is failing