C语言用fopen无法打开文件

fopen函数无法打开文件啊，我已经在本地磁盘建好了三个文档，却一直给我报Error

#include
int main()
{
    FILE *fp1;
    FILE *fp2;
    FILE *fp3;
    
    fp1 = fopen("ml.txt","r");
    fp2 = fopen("m2.txt","r"); 
    fp3 = fopen("m3.txt","r");
    
    if(fp1 == NULL||fp2==NULL||fp3==NULL)
    {printf("Error");
    }
    
    int i=0,j=0;
    char a[100],b[100],c[100];
    char ch1,ch2,ch3;
    
    ch1 = fgetc(fp1);
    while(ch1!= EOF)
    {
     printf("%c",ch1);
    }
    for(i=0;i<100;i++)
    
    fclose(fp1);fclose(fp2);fclose(fp3);
 }

fp1 = fopen("d:\\ml.txt","r");
    fp2 = fopen("d:\\m2.txt","r"); 
    fp3 = fopen("d:\\m3.txt","r");

在d盘建立3个文件，测试一下是否能够打开，如能够打开，说明原来所建的文件路径不对，实际上建一个文件进行测试就行