俺もIISにphp入れてるんだけどfopenやfcloseって使えないっぽい？

Warning: fopen(count.txt) [function.fopen]: failed to open stream: Permission denied in C:\hp\count.php on line 9
Warning: fwrite(): supplied argument is not a valid stream resource in C:\hp\count.php on line 10
Warning: fclose(): supplied argument is not a valid stream resource in C:\hp\count.php on line 11

こんなのが出る。カウンタ増やすプログラムだけどカウンタ増えない。