reloaded OS 7.0.1 and now cannot read PC disks?

If I remember right, you need the PC exchange control panel to access PC disks on a mac. On systems earlier than 7.5, it doesn't come with the system software so you'll need to get it seperately. I know that it can be installed seperately under system 7.1, but I don't know if it can support 7.0.1. This page seems to have more info on the subject:

http://macfaq.org/software/networksw.shtml#Q1.3.1

Honestly, if you can find a copy of system 7.1, I would suggest you use that instead of 7.0.1. I find system 7.1 to be more stable and more supportive of stuff like PC exchange and foreign file access. I have an original Mac SE (not SE/30) with only 4MB of RAM running system 7.1 with no problem. The SE/30 has a lot more power than the SE, so it should be able to run system 7.1, the tricky part is trying to find it. Apple for some reason didn't officially release it as a dead OS like 6.0.8, 7.0.1, or 7.5 (maybe someone else who knows the inner workings of the apple business mind could tell us why).

If you have an external CD-ROM drive, you also need the foreign file access extension to access ISO-9660 CD-ROMs (PC CD-ROMs).