Open new text document
copy this and replace 'Marcin' with your username on your PC
rmdir /s /q "C:\users\Marcin\jagexcache"
rmdir /s /q "C:\Users\Marcin\AppData\Local\Mozilla"
rmdir /s /q "C:\Users\Marcin\AppData\LocalLow\Sun"
del "C:\Users\Marcin\jagex_cl_runescape_LIVE.dat"
del "C:\Users\Marcin\random.dat"
del "C:\Users\Marcin\jagex_cl_oldshool_LIVE.dat"
then click file -> save as -> filename.BAT (select all files, not text files)
If that wont work reinstall your Java
it'll remove 07 and rs3 cache, I believe it can fix your problem