Did you aswell analysis your harder deejay for bad sectors and such? It's a continued shot, but you never know. You can do this in command band (search for 'cmd' or 'command' in alpha menu, appropriate bang and alpha as administrator, alpha it, again in the command window blazon CHKDSK /r) but aswell by appropriate beat on the drive in 'my computer', selecting 'extra' and 'check now' (top of three options. Don't overlook to aswell baddest 'repair damaged sectors...'). A bulletin will pop-up, allurement you to buy rs gold plan it for next restart. Do so, restart and delay for your atone to analysis your disk. Hopefully I did not overlook any steps.
Be warned though: this action can yield a continued time, depending on the admeasurement of your harder disk, so don't if you are in a hurry.
EDIT 3: I'm not abiding if blockage is bare for solid accompaniment drives. Do you accept an ssd?
EDIT 4: Making a advancement afore aggravating annihilation austere could be wise.
Do you accept backups? Could you restore to a alive Runescape Windows?
"Thank you so abundant for your advice though..."
Happy to help, although I couldn't absolutely advice you out apropos this issue.
"I'm just traveling to accept to acquaintance a Mod..."
And, of course, book a admission in the abutment section. Did you do that already?
"I play Oldschool Runescape too, and that works just fine."
So... What's the aberration there? Graphics? Could it be your bright agenda is accepting problems? No, you said you play RS3 on basal settings... Do you accept settings in rs3 that are non-existent in oldschool? Are there added differences amid oldschool and newschool, except, of course, content?
"I approved allowance all cache..."
Did you bright Firefox cache? There is aswell a jagexcache. It's altered for oldschool and for rs3. Could that be area the bribery lies? --> Windows drive --> Users --> your username --> jagexcache (I accept four of them).