I have just installed Fedora on a partition of my hard drive. However, upon trying to compile a program (using make) that I had downloaded (clustalw) I realized that I didn't have gcc. I tried to install it from my second disk, but there was an error. Now, when trying to make I get the following message. param.h:206: error: `NULL' undeclared here (not in a function) param.h:206: error: initializer element is not constant param.h:206: error: (near initialization for `res_cat1[9]') param.h:220: error: `NULL' undeclared here (not in a function) param.h:220: error: initializer element is not constant param.h:220: error: (near initialization for `res_cat2[11]') param.h:302: error: `NULL' undeclared here (not in a function) .................. then same thing with interface.c instead of param.h I cannot install it from the disk for some reason. I have also tried using an rpm, but have failed. Any suggestions?????????? Thanks,