diff --git a/Common/File/FileUtil.cpp b/Common/File/FileUtil.cpp
index e38712767e..ebb093bd44 100644
--- a/Common/File/FileUtil.cpp
+++ b/Common/File/FileUtil.cpp
@@ -245,7 +245,8 @@ bool IsDirectory(const std::string &filename)
 	std::wstring copy = ConvertUTF8ToWString(fn);
 	WIN32_FILE_ATTRIBUTE_DATA data{};
 	if (!GetFileAttributesEx(copy.c_str(), GetFileExInfoStandard, &data) || data.dwFileAttributes == INVALID_FILE_ATTRIBUTES) {
-		WARN_LOG(COMMON, "GetFileAttributes failed on %s: %08x", fn.c_str(), (uint32_t)GetLastError());
+		auto err = GetLastError();
+		WARN_LOG(COMMON, "GetFileAttributes failed on %s: %08x %s", fn.c_str(), (uint32_t)err, GetStringErrorMsg(err).c_str());
 		return false;
 	}
 	DWORD result = data.dwFileAttributes;
@@ -311,7 +312,7 @@ bool CreateDir(const std::string &path)
 		WARN_LOG(COMMON, "CreateDir: CreateDirectory failed on %s: already exists", path.c_str());
 		return true;
 	}
-	ERROR_LOG(COMMON, "CreateDir: CreateDirectory failed on %s: %08x", path.c_str(), (uint32_t)error);
+	ERROR_LOG(COMMON, "CreateDir: CreateDirectory failed on %s: %08x %s", path.c_str(), (uint32_t)error, GetStringErrorMsg(error).c_str());
 	return false;
 #else
 	if (mkdir(fn.c_str(), 0755) == 0)
diff --git a/Common/Net/HTTPClient.cpp b/Common/Net/HTTPClient.cpp
index fb86f96d6f..3dd540f326 100644
--- a/Common/Net/HTTPClient.cpp
+++ b/Common/Net/HTTPClient.cpp
@@ -337,17 +337,14 @@ int Client::ReadResponseHeaders(net::Buffer *readbuf, std::vector<std::string> &
 	// Snarf all the data we can into RAM. A little unsafe but hey.
 	static constexpr float CANCEL_INTERVAL = 0.25f;
 	bool ready = false;
-	double leftTimeout = dataTimeout_;
+	double endTimeout = time_now_d() + dataTimeout_;
 	while (!ready) {
 		if (cancelled && *cancelled)
 			return -1;
 		ready = fd_util::WaitUntilReady(sock(), CANCEL_INTERVAL, false);
-		if (!ready && leftTimeout >= 0.0) {
-			leftTimeout -= CANCEL_INTERVAL;
-			if (leftTimeout < 0) {
-				ERROR_LOG(IO, "HTTP headers timed out");
-				return -1;
-			}
+		if (!ready && time_now_d() > endTimeout) {
+			ERROR_LOG(IO, "HTTP headers timed out");
+			return -1;
 		}
 	};
 	// Let's hope all the headers are available in a single packet...
diff --git a/Common/Net/HTTPClient.h b/Common/Net/HTTPClient.h
index 342f8f5604..2cc8901f05 100644
--- a/Common/Net/HTTPClient.h
+++ b/Common/Net/HTTPClient.h
@@ -75,7 +75,7 @@ public:
 protected:
 	std::string userAgent_;
 	const char *httpVersion_;
-	double dataTimeout_ = -1.0;
+	double dataTimeout_ = 900.0;
 };
 
 // Not particularly efficient, but hey - it's a background download, that's pretty cool :P
diff --git a/Common/Net/NetBuffer.cpp b/Common/Net/NetBuffer.cpp
index 08059e76c8..377de82b5c 100644
--- a/Common/Net/NetBuffer.cpp
+++ b/Common/Net/NetBuffer.cpp
@@ -25,17 +25,14 @@ bool Buffer::FlushSocket(uintptr_t sock, double timeout, bool *cancelled) {
 	static constexpr float CANCEL_INTERVAL = 0.25f;
 	for (size_t pos = 0, end = data_.size(); pos < end; ) {
 		bool ready = false;
-		double leftTimeout = timeout;
-		while (!ready && (leftTimeout >= 0 || cancelled)) {
+		double endTimeout = time_now_d() + timeout;
+		while (!ready) {
 			if (cancelled && *cancelled)
 				return false;
 			ready = fd_util::WaitUntilReady(sock, CANCEL_INTERVAL, true);
-			if (!ready && leftTimeout >= 0.0) {
-				leftTimeout -= CANCEL_INTERVAL;
-				if (leftTimeout < 0) {
-					ERROR_LOG(IO, "FlushSocket timed out");
-					return false;
-				}
+			if (!ready && time_now_d() > endTimeout) {
+				ERROR_LOG(IO, "FlushSocket timed out");
+				return false;
 			}
 		}
 		int sent = send(sock, &data_[pos], (int)(end - pos), MSG_NOSIGNAL);
@@ -44,40 +41,11 @@ bool Buffer::FlushSocket(uintptr_t sock, double timeout, bool *cancelled) {
 			return false;
 		}
 		pos += sent;
-
-		// Buffer full, don't spin.
-		if (sent == 0 && timeout < 0.0) {
-			sleep_ms(1);
-		}
 	}
 	data_.resize(0);
 	return true;
 }
 
-bool Buffer::ReadAll(int fd, int hintSize) {
-	std::vector<char> buf;
-	if (hintSize >= 65536 * 16) {
-		buf.resize(65536);
-	} else if (hintSize >= 1024 * 16) {
-		buf.resize(hintSize / 16);
-	} else {
-		buf.resize(4096);
-	}
-
-	while (true) {
-		int retval = recv(fd, &buf[0], (int)buf.size(), MSG_NOSIGNAL);
-		if (retval == 0) {
-			break;
-		} else if (retval < 0) {
-			ERROR_LOG(IO, "Error reading from buffer: %i", retval);
-			return false;
-		}
-		char *p = Append((size_t)retval);
-		memcpy(p, &buf[0], retval);
-	}
-	return true;
-}
-
 bool Buffer::ReadAllWithProgress(int fd, int knownSize, float *progress, bool *cancelled) {
 	static constexpr float CANCEL_INTERVAL = 0.25f;
 	std::vector<char> buf;
diff --git a/Common/Net/NetBuffer.h b/Common/Net/NetBuffer.h
index 3575dceddd..3ee7390aa3 100644
--- a/Common/Net/NetBuffer.h
+++ b/Common/Net/NetBuffer.h
@@ -6,9 +6,8 @@ namespace net {
 
 class Buffer : public ::Buffer {
 public:
-	bool FlushSocket(uintptr_t sock, double timeout = -1.0, bool *cancelled = nullptr);
+	bool FlushSocket(uintptr_t sock, double timeout, bool *cancelled = nullptr);
 
-	bool ReadAll(int fd, int hintSize = 0);
 	bool ReadAllWithProgress(int fd, int knownSize, float *progress, bool *cancelled);
 
 	// < 0: error
diff --git a/Core/FileSystems/DirectoryFileSystem.cpp b/Core/FileSystems/DirectoryFileSystem.cpp
index 89869e7ca1..40184ee07d 100644
--- a/Core/FileSystems/DirectoryFileSystem.cpp
+++ b/Core/FileSystems/DirectoryFileSystem.cpp
@@ -36,6 +36,7 @@
 #include "Common/File/FileUtil.h"
 #include "Common/File/DiskFree.h"
 #include "Common/File/VFS/VFS.h"
+#include "Common/SysError.h"
 #include "Core/FileSystems/DirectoryFileSystem.h"
 #include "Core/FileSystems/ISOFileSystem.h"
 #include "Core/HLE/sceKernel.h"
@@ -631,7 +632,8 @@ int DirectoryFileSystem::OpenFile(std::string filename, FileAccess access, const
 	err = ReplayApplyDisk(ReplayAction::FILE_OPEN, err, CoreTiming::GetGlobalTimeUs());
 	if (err != 0) {
 #ifdef _WIN32
-		ERROR_LOG(FILESYS, "DirectoryFileSystem::OpenFile: FAILED, %i - access = %i", (int)GetLastError(), (int)access);
+		auto win32err = GetLastError();
+		ERROR_LOG(FILESYS, "DirectoryFileSystem::OpenFile: FAILED, %i - access = %i, %s", (int)win32err, (int)access, GetStringErrorMsg(win32err).c_str());
 #else
 		ERROR_LOG(FILESYS, "DirectoryFileSystem::OpenFile: FAILED, %i - access = %i", errno, (int)access);
 #endif
diff --git a/Core/Instance.cpp b/Core/Instance.cpp
index a36aca0049..e8a5590dbd 100644
--- a/Core/Instance.cpp
+++ b/Core/Instance.cpp
@@ -25,14 +25,13 @@
 #include <fcntl.h>
 #endif
 
-#include "Common/Log.h"
-
 #if PPSSPP_PLATFORM(WINDOWS)
-
 #include "Common/CommonWindows.h"
-
 #endif
 
+#include "Common/Log.h"
+#include "Common/SysError.h"
+
 #include <cstdint>
 
 uint8_t PPSSPP_ID = 0;
@@ -65,7 +64,8 @@ static bool UpdateInstanceCounter(void (*callback)(volatile InstanceInfo *)) {
 		sizeof(InstanceInfo));
 
 	if (!buf) {
-		ERROR_LOG(SCENET, "Could not map view of file %s (%08x)", ID_SHM_NAME, (uint32_t)GetLastError());
+		auto err = GetLastError();
+		ERROR_LOG(SCENET, "Could not map view of file %s, %08x %s", ID_SHM_NAME, (uint32_t)err, GetStringErrorMsg(err).c_str());
 		return false;
 	}
 
@@ -137,7 +137,7 @@ void InitInstanceCounter() {
 
 	DWORD lasterr = GetLastError();
 	if (!hIDMapFile) {
-		ERROR_LOG(SCENET, "Could not create %s file mapping object (%08x)", ID_SHM_NAME, (uint32_t)lasterr);
+		ERROR_LOG(SCENET, "Could not create %s file mapping object, %08x %s", ID_SHM_NAME, (uint32_t)lasterr, GetStringErrorMsg(lasterr).c_str());
 		PPSSPP_ID = 1;
 		return;
 	}