Reaper will not play

first test: open reaper with no project load one wav or mp3 on one track If it will play that, there is a problem with your other project If it will not play that single wav, then the problem is with your audio interface and it's set up.... if it is a real audio interface you might need to re install it's drivers

I loaded an mp3, it didn't work. If it was bad drivers wouldn't the counter move and the cursor and just no sound output? Or is that too simplistic of thinking? Forgot to add info: WinXP 32 bit, ASUS Xonar D2 PCI soundcard.

I don't know anything about that sound card, but I do know that any sound card depends on it's drivers, AND that it can often happen that the drivers get corrupted. When this happens reaper will just sit there. So I highly suggest, getting the latest drivers and doing a fresh install of them.

I already had the latest drivers, but, I did as suggested. It still doesn't work. I also tried resetting Reaper to default settings, which didn't change it either. Add: I took the wav file into audacity to compress and normalize. I am unsure if that coiuld cause a problem? Although Reaper is not "playing" any project files, as I have tried others, "just in case."

I get that 

In my case it seems to be where Reaper loses the clock from the interface. What I do (I have a Focusrite Pro40) is change the setting in the Focusrite from internal to external sync, then back again, and it resets the sync and all is good. Don't know why it happens though, and it's really irritating. It's not a Reaper problem because I use Wavelab too and it happens there too so it's something to do with the I/f or Apple interfering.

"Play cursor not moving when I hit Play" usually means that REAPER can't communicate with the soundcard - Reaper can't access it, it's not there or not available because another application uses it (the latter being the top reason for problems like this on Windows Vista and higher). Make sure not other application (including web browsers) using sound is running when REAPER uses the ASIO driver. Other causes are e.g. the Wavetable Synth is enabled in Preferences->MIDI Devices or the device is disconnecting randomly due to power saving settings, bad connection or USB power issues.

totally agtee with what Ollie says, and... trouble shooting can be fun... I'd like to see a screen shot of your Audio pref's set up in the reaper preferences... also, would you try to set the audio driver to WASAPI and see what you get...? I am on Win7 Pro 64 bit, and do not find it needed to 'turn off windows sounds' but I do turn off the sound card that is built in to my motherboard... I do that in device manager. So the only sound device is my m-audio profire 2626. One instance of reaper uses the ASIO driver for that... AND I can have other apps running at the same time using one of the non asio drivers...

grandchildren...... 

Stopped windows sounds, no go. Tried to change from waveout to asio to WDM to DirectSound, none worked. I uninstalled then reinstalled set to asio, runs like it should. My granddaughter(2y.o.) evidently had hit keys on my keyboard. She evidently changed something I couldn't find. Thank you all for the help. I really appreciate it. P.S. It seems that WASAPI is for Win7 and Vista, at least when I pulled it up in preferences. The ASIO driver for my card has worked very well, so I will probably stick with it. Does anybody know if the WASAPI is supposed to work in XP? I couldn't find it at Microsoft's site, so unsure. @hopi: I am running XP, but, if I recall correctly shutting windows sounds in Win7 is under the personalization screen, under Sound and Audio. I also found this: Type in mmsys.cpl into the start menu search box, and hit enter, click the Sounds Tab(I haven't done much in Win7 because my XP stays so solid, no internet or otherwise on it).