32 bit Reaper on 64 bit W7 system. I don't recall altiverb giving me a 32/64 bit choice on install, I assume it installed as 64 bit here is the error report - Problem signature: Problem Event Name: APPCRASH Application Name: reaper.exe Application Version: 4.7.2.0 Application Timestamp: 53f3fdbe Fault Module Name: StackHash_0c47 Fault Module Version: 0.0.0.0 Fault Module Timestamp: 00000000 Exception Code: c0000005 Exception Offset: 66c3c11b OS Version: 6.1.7601.2.1.0.768.3 Locale ID: 1033 Additional Information 1: 0c47 Additional Information 2: 0c47ecc18b31d3b3d50c3a36f49e3b09 Additional Information 3: 20a4 Additional Information 4: 20a430ebafad6471c137f74bcadee1c7 FROM CRASH LOG: Faulting application name: reaper.exe, version: 4.7.2.0, time stamp: 0x53f3fdbe Faulting module name: unknown, version: 0.0.0.0, time stamp: 0x00000000 Exception code: 0xc0000005 Fault offset: 0x66c3c11b Faulting process id: 0x1a3c Faulting application start time: 0x01cfc60feadbcd6f Faulting application path: C:\Program Files (x86)\REAPER\reaper.exe Faulting module path: unknown Report Id: b988e8ca-3203-11e4-8138-70188ba36956