diff --git a/clang/test/Driver/riscv32-toolchain.c b/clang/test/Driver/riscv32-toolchain.c
index 4eefa006c129f5..1e6c8deb3de375 100644
--- a/clang/test/Driver/riscv32-toolchain.c
+++ b/clang/test/Driver/riscv32-toolchain.c
@@ -1,3 +1,4 @@
+// UNSUPPORTED: system-windows
 // A basic clang -cc1 command-line, and simple environment check.
 
 // RUN: %clang %s -### -no-canonical-prefixes --target=riscv32 \
@@ -74,7 +75,7 @@
 // CXX-RV32-BAREMETAL-NOSYSROOT-ILP32: "-lstdc++" "--start-group" "-lc" "-lgloss" "--end-group" "-lgcc"
 // CXX-RV32-BAREMETAL-NOSYSROOT-ILP32: "{{.*}}/Inputs/basic_riscv32_tree/lib/gcc/riscv32-unknown-elf/8.0.1{{/|\\\\}}crtend.o"
 
-// RUN: %clang %s -### -fuse-ld=ld -no-pie \
+// RUN: env "PATH=" %clang %s -### -fuse-ld=ld -no-pie \
 // RUN:   --target=riscv32-unknown-linux-gnu --rtlib=platform -mabi=ilp32 \
 // RUN:   --gcc-toolchain=%S/Inputs/multilib_riscv_linux_sdk \
 // RUN:   --sysroot=%S/Inputs/multilib_riscv_linux_sdk/sysroot 2>&1 \
@@ -89,7 +90,7 @@
 // C-RV32-LINUX-MULTI-ILP32: "-L{{.*}}/Inputs/multilib_riscv_linux_sdk/sysroot/lib32/ilp32"
 // C-RV32-LINUX-MULTI-ILP32: "-L{{.*}}/Inputs/multilib_riscv_linux_sdk/sysroot/usr/lib32/ilp32"
 
-// RUN: %clang %s -### -fuse-ld=ld -no-pie \
+// RUN: env "PATH=" %clang %s -### -fuse-ld=ld -no-pie \
 // RUN:   --target=riscv32-unknown-linux-gnu --rtlib=platform -march=rv32imafd \
 // RUN:   --gcc-toolchain=%S/Inputs/multilib_riscv_linux_sdk \
 // RUN:   --sysroot=%S/Inputs/multilib_riscv_linux_sdk/sysroot 2>&1 \
@@ -104,7 +105,7 @@
 // C-RV32-LINUX-MULTI-ILP32D: "-L{{.*}}/Inputs/multilib_riscv_linux_sdk/sysroot/lib32/ilp32d"
 // C-RV32-LINUX-MULTI-ILP32D: "-L{{.*}}/Inputs/multilib_riscv_linux_sdk/sysroot/usr/lib32/ilp32d"
 
-// RUN: %clang %s -### -fuse-ld=ld \
+// RUN: env "PATH=" %clang %s -### -fuse-ld=ld \
 // RUN:   --target=riscv32-unknown-elf --rtlib=platform --sysroot= \
 // RUN:   --gcc-toolchain=%S/Inputs/multilib_riscv_elf_sdk 2>&1 \
 // RUN:   | FileCheck -check-prefix=C-RV32I-BAREMETAL-MULTI-ILP32 %s
@@ -118,7 +119,7 @@
 // C-RV32I-BAREMETAL-MULTI-ILP32: "--start-group" "-lc" "-lgloss" "--end-group" "-lgcc"
 // C-RV32I-BAREMETAL-MULTI-ILP32: "{{.*}}/Inputs/multilib_riscv_elf_sdk/lib/gcc/riscv64-unknown-elf/8.2.0/rv32imac/ilp32{{/|\\\\}}crtend.o"
 
-// RUN: %clang %s -### -fuse-ld=ld \
+// RUN: env "PATH=" %clang %s -### -fuse-ld=ld \
 // RUN:   --target=riscv32-unknown-elf --rtlib=platform --sysroot= \
 // RUN:   -march=rv32im -mabi=ilp32\
 // RUN:   --gcc-toolchain=%S/Inputs/multilib_riscv_elf_sdk 2>&1 \
@@ -133,7 +134,7 @@
 // C-RV32IM-BAREMETAL-MULTI-ILP32: "--start-group" "-lc" "-lgloss" "--end-group" "-lgcc"
 // C-RV32IM-BAREMETAL-MULTI-ILP32: "{{.*}}/Inputs/multilib_riscv_elf_sdk/lib/gcc/riscv64-unknown-elf/8.2.0/rv32im/ilp32{{/|\\\\}}crtend.o"
 
-// RUN: %clang %s -### -fuse-ld=ld \
+// RUN: env "PATH=" %clang %s -### -fuse-ld=ld \
 // RUN:   --target=riscv32-unknown-elf --rtlib=platform --sysroot= \
 // RUN:   -march=rv32iac -mabi=ilp32\
 // RUN:   --gcc-toolchain=%S/Inputs/multilib_riscv_elf_sdk 2>&1 \
@@ -148,7 +149,7 @@
 // C-RV32IAC-BAREMETAL-MULTI-ILP32: "--start-group" "-lc" "-lgloss" "--end-group" "-lgcc"
 // C-RV32IAC-BAREMETAL-MULTI-ILP32: "{{.*}}/Inputs/multilib_riscv_elf_sdk/lib/gcc/riscv64-unknown-elf/8.2.0/rv32iac/ilp32{{/|\\\\}}crtend.o"
 
-// RUN: %clang %s -### -fuse-ld=ld \
+// RUN: env "PATH=" %clang %s -### -fuse-ld=ld \
 // RUN:   --target=riscv32-unknown-elf --rtlib=platform --sysroot= \
 // RUN:   -march=rv32imac -mabi=ilp32\
 // RUN:   --gcc-toolchain=%S/Inputs/multilib_riscv_elf_sdk 2>&1 \
@@ -163,7 +164,7 @@
 // C-RV32IMAC-BAREMETAL-MULTI-ILP32: "--start-group" "-lc" "-lgloss" "--end-group" "-lgcc"
 // C-RV32IMAC-BAREMETAL-MULTI-ILP32: "{{.*}}/Inputs/multilib_riscv_elf_sdk/lib/gcc/riscv64-unknown-elf/8.2.0/rv32imac/ilp32{{/|\\\\}}crtend.o"
 
-// RUN: %clang %s -### -fuse-ld=ld \
+// RUN: env "PATH=" %clang %s -### -fuse-ld=ld \
 // RUN:   --target=riscv32-unknown-elf --rtlib=platform --sysroot= \
 // RUN:   -march=rv32imafc -mabi=ilp32f \
 // RUN:   --gcc-toolchain=%S/Inputs/multilib_riscv_elf_sdk 2>&1 \
diff --git a/clang/test/Driver/riscv64-toolchain.c b/clang/test/Driver/riscv64-toolchain.c
index d35e1940318572..4c7c04500d6ee7 100644
--- a/clang/test/Driver/riscv64-toolchain.c
+++ b/clang/test/Driver/riscv64-toolchain.c
@@ -1,3 +1,4 @@
+// UNSUPPORTED: system-windows
 // A basic clang -cc1 command-line, and simple environment check.
 
 // RUN: %clang %s -### -no-canonical-prefixes --target=riscv64 \
@@ -104,7 +105,7 @@
 // C-RV64-LINUX-MULTI-LP64D: "-L{{.*}}/Inputs/multilib_riscv_linux_sdk/sysroot/lib64/lp64d"
 // C-RV64-LINUX-MULTI-LP64D: "-L{{.*}}/Inputs/multilib_riscv_linux_sdk/sysroot/usr/lib64/lp64d"
 
-// RUN: %clang %s -### -fuse-ld=ld \
+// RUN: env "PATH=" %clang %s -### -fuse-ld=ld \
 // RUN:   --target=riscv64-unknown-elf --rtlib=platform --sysroot= \
 // RUN:   -march=rv64imac -mabi=lp64\
 // RUN:   --gcc-toolchain=%S/Inputs/multilib_riscv_elf_sdk 2>&1 \
@@ -119,7 +120,7 @@
 // C-RV64IMAC-BAREMETAL-MULTI-LP64: "--start-group" "-lc" "-lgloss" "--end-group" "-lgcc"
 // C-RV64IMAC-BAREMETAL-MULTI-LP64: "{{.*}}/Inputs/multilib_riscv_elf_sdk/lib/gcc/riscv64-unknown-elf/8.2.0/rv64imac/lp64{{/|\\\\}}crtend.o"
 
-// RUN: %clang %s -### -fuse-ld=ld \
+// RUN: env "PATH=" %clang %s -### -fuse-ld=ld \
 // RUN:   --target=riscv64-unknown-elf --rtlib=platform --sysroot= \
 // RUN:   -march=rv64imafdc -mabi=lp64d \
 // RUN:   --gcc-toolchain=%S/Inputs/multilib_riscv_elf_sdk 2>&1 \