SALAM FRIENDS

I have the following problems with my system
1 when I start my system cpu gets on but don’t shoe any display
On monitor after trying again again some time it show display
2 When I install any soft wear task manager stop working
3 system restart automatically after some time or hanged
4 speed is also slow
5 8603 pointing device error comes every time on start
6 if I restart system it gets on first time
I tried all this
Reinstall window many time
I change window cd
Keep system in sun light full day
I change drive also from c to d
I also format al drives
Scan system with nod 32 and kasper antivirus

So brother help me I don’t know much about computer

I shall be very much thank full to you all