HN isn't the place to ask for this type of situation.
If you look into sites like: http://tomshardware.com you will find a lot more info.
Right now, I can't actually think of any workarounds, but you could possibly do a workaround through the BIOS (again, that is just an assumption of mine).
As per your partitions, there's too many (for me that is). It makes sense to keep your failover on an external HDD.
>"4 GB RAM and i5 processor became slow as hell."
That is somewhat of a powerful machine, I'm surprised things like that slow up. One of my machines still runs on DDR1 RAM and it works pretty quick (for me that is).