Ok this problem is very recent and I have no idea what happend.
When i checked the specs of this pc before when my dad was going to buy this laptop for my birthday it had 8GB of ram and it did as i checked in the system properties. 3 years later my laptop started being slower and i checked the system properties it said I have 4GB of ram!!!
Specs
Lenovo Z510 ideapad (laptop)
Intel Core i7-4702MQ 2.20Ghz
Geforce GT740M
1TB hard drive
8GB ram