diff --git a/AU/AU.psm1 b/AU/AU.psm1
index d29f0b09..3fc50a54 100644
--- a/AU/AU.psm1
+++ b/AU/AU.psm1
@@ -2,5 +2,5 @@
 
 $paths = "Private", "Public"
 foreach ($path in $paths) {
-    Get-ChildItem $PSScriptRoot\$path\*.ps1 | ForEach-Object { . $_.FullName }
+    Get-ChildItem ([System.IO.Path]::Combine($PSScriptRoot, $path, '*.ps1')) | ForEach-Object { . $_.FullName }
 }
diff --git a/AU/Plugins/Report.ps1 b/AU/Plugins/Report.ps1
index af72f860..f4c184f5 100644
--- a/AU/Plugins/Report.ps1
+++ b/AU/Plugins/Report.ps1
@@ -24,7 +24,7 @@ param(
 
 Write-Host "Saving $Type report: $Path"
 
-$Type = "$PSScriptRoot\Report\$Type.ps1"
+$Type = ([System.IO.Path]::Combine($PSScriptRoot, 'Report', "$Type.ps1"))
 if (!(Test-Path $Type )) { throw "Report type not found: '$Type" }
 
 $result = & $Type
diff --git a/AU/Plugins/Report/markdown.ps1 b/AU/Plugins/Report/markdown.ps1
index e8cacdfe..d69a27f2 100644
--- a/AU/Plugins/Report/markdown.ps1
+++ b/AU/Plugins/Report/markdown.ps1
@@ -1,4 +1,4 @@
-. $PSScriptRoot\markdown_funcs.ps1
+. (Join-Path $PSScriptRoot 'markdown_funcs.ps1')
 
 $Github_UserRepo = $Params.Github_UserRepo
 $UserMessage     = $Params.UserMessage
diff --git a/AU/Private/AUPackage.ps1 b/AU/Private/AUPackage.ps1
index 358b589e..36bc7b0b 100644
--- a/AU/Private/AUPackage.ps1
+++ b/AU/Private/AUPackage.ps1
@@ -20,13 +20,13 @@ class AUPackage {
         $this.Path = $Path
         $this.Name = Split-Path -Leaf $Path
 
-        $this.NuspecPath = '{0}\{1}.nuspec' -f $this.Path, $this.Name
+        $this.NuspecPath = '{0}{2}{1}.nuspec' -f $this.Path, $this.Name, [IO.Path]::DirectorySeparatorChar
         if (!(Get-Item $this.NuspecPath -ea ignore)) { throw 'No nuspec file found in the package directory' }
 
         $this.NuspecXml     = [AUPackage]::LoadNuspecFile( $this.NuspecPath )
         $this.NuspecVersion = $this.NuspecXml.package.metadata.version
 
-        $this.StreamsPath = '{0}\{1}.json' -f $this.Path, $this.Name
+        $this.StreamsPath = '{0}{2}{1}.json' -f $this.Path, $this.Name, [IO.Path]::DirectorySeparatorChar
         $this.Streams     = [AUPackage]::LoadStreams( $this.StreamsPath )
     }
 
@@ -76,20 +76,20 @@ class AUPackage {
     }
 
     Backup()  { 
-        $d = "$Env:TEMP\au\" + $this.Name
+        $d = ([System.IO.Path]::Combine([System.IO.Path]::GetTempPath(), 'au', $this.Name))
 
-        Remove-Item $d\* -Recurse -ea 0
-        Copy-Item . $d\_backup -Recurse 
+        Remove-Item (Join-Path $d '*') -Recurse -ea 0
+        Copy-Item . (Join-Path $d '_backup') -Recurse 
     }
 
     [string] SaveAndRestore() { 
-        $d = "$Env:TEMP\au\" + $this.Name
+        $d = ([System.IO.Path]::Combine([System.IO.Path]::GetTempPath(), 'au', $this.Name))
 
-        Copy-Item . $d\_output -Recurse 
-        Remove-Item .\* -Recurse
-        Copy-Item $d\_backup\* . -Recurse 
+        Copy-Item . (Join-Path $d '_output') -Recurse 
+        Remove-Item (Join-Path '.' '*') -Recurse
+        Copy-Item ([System.IO.Path]::Combine($d, '_backup', '*')) . -Recurse 
         
-        return "$d\_output"
+        return (Join-Path $d '_output')
     }
 
     AUPackage( [hashtable] $obj ) {
diff --git a/AU/Public/Get-AUPackages.ps1 b/AU/Public/Get-AUPackages.ps1
index 54f72000..573b7a46 100644
--- a/AU/Public/Get-AUPackages.ps1
+++ b/AU/Public/Get-AUPackages.ps1
@@ -28,7 +28,7 @@ function Get-AUPackages( [string[]] $Name ) {
     $root = $global:au_root
     if (!$root) { $root = $pwd }
 
-    Get-ChildItem $root\*\update.ps1 | ForEach-Object {
+    Get-ChildItem ([System.IO.Path]::Combine($root, '*', 'update.ps1')) | ForEach-Object {
         $packageDir = Get-Item (Split-Path $_)
 
         if ($Name -and $Name.Length -gt 0) {
diff --git a/AU/Public/Get-RemoteFiles.ps1 b/AU/Public/Get-RemoteFiles.ps1
index 7c92179b..a94dbbc4 100644
--- a/AU/Public/Get-RemoteFiles.ps1
+++ b/AU/Public/Get-RemoteFiles.ps1
@@ -58,7 +58,8 @@ function Get-RemoteFiles {
 
     if ($Purge) {
         Write-Host 'Purging' $ext
-        Remove-Item -Force "$toolsPath\*.$ext" -ea ignore
+        $purgePath = "$toolsPath{0}*.$ext" -f [IO.Path]::DirectorySeparatorChar
+        Remove-Item -Force $purgePath -ea ignore
     }
 
     function headers($client) {
@@ -74,7 +75,7 @@ function Get-RemoteFiles {
             headers($client)
             $base_name = name4url $Latest.Url32
             $file_name = "{0}{2}.{1}" -f $base_name, $ext, $(if ($NoSuffix) { '' } else {'_x32'})
-            $file_path = "$toolsPath\$file_name"
+            $file_path = Join-Path $toolsPath $file_name
 
             Write-Host "Downloading to $file_name -" $Latest.Url32
             $client.DownloadFile($Latest.URL32, $file_path)
@@ -87,7 +88,7 @@ function Get-RemoteFiles {
             headers($client)
             $base_name = name4url $Latest.Url64
             $file_name = "{0}{2}.{1}" -f $base_name, $ext, $(if ($NoSuffix) { '' } else {'_x64'})
-            $file_path = "$toolsPath\$file_name"
+            $file_path = Join-Path $toolsPath $file_name
 
             Write-Host "Downloading to $file_name -" $Latest.Url64
             $client.DownloadFile($Latest.URL64, $file_path)
diff --git a/AU/Public/Push-Package.ps1 b/AU/Public/Push-Package.ps1
index c74c59f4..7a599850 100644
--- a/AU/Public/Push-Package.ps1
+++ b/AU/Public/Push-Package.ps1
@@ -14,7 +14,7 @@ function Push-Package() {
         [switch] $All
     )
     $api_key =  if (Test-Path api_key) { Get-Content api_key }
-                elseif (Test-Path ..\api_key) { Get-Content ..\api_key }
+                elseif (Test-Path (Join-Path '..' 'api_key')) { Get-Content (Join-Path '..' 'api_key') }
                 elseif ($Env:api_key) { $Env:api_key }
 
     $push_url =  if ($Env:au_PushUrl) { $Env:au_PushUrl }
diff --git a/AU/Public/Test-Package.ps1 b/AU/Public/Test-Package.ps1
index e1ea09aa..91019b46 100644
--- a/AU/Public/Test-Package.ps1
+++ b/AU/Public/Test-Package.ps1
@@ -65,7 +65,7 @@ function Test-Package {
         Write-Host "Nuspec file given, running choco pack"
         choco pack -r $Nu.FullName --OutputDirectory $Nu.DirectoryName | Write-Host
         if ($LASTEXITCODE -ne 0) { throw "choco pack failed with $LastExitCode"}
-        $Nu = Get-Item "$($Nu.DirectoryName)\*.nupkg" | Sort-Object -Property CreationTime -Descending | Select-Object -First 1
+        $Nu = Get-Item ([System.IO.Path]::Combine($Nu.DirectoryName, '*.nupkg')) | Sort-Object -Property CreationTime -Descending | Select-Object -First 1
     } elseif ($Nu.Extension -ne '.nupkg') { throw "File is not nupkg or nuspec file" }
 
     #At this point Nu is nupkg file
@@ -85,13 +85,13 @@ function Test-Package {
 
         if (!$VagrantNoClear)  {
             Write-Host 'Removing existing vagrant packages'
-            Remove-Item $Vagrant\packages\*.nupkg -ea ignore
-            Remove-Item $Vagrant\packages\*.xml   -ea ignore
+            Remove-Item ([System.IO.Path]::Combine($Vagrant, 'packages', '*.nupkg')) -ea ignore
+            Remove-Item ([System.IO.Path]::Combine($Vagrant, 'packages', '*.xml'))   -ea ignore
         }
 
-        Copy-Item $Nu $Vagrant\packages
+        Copy-Item $Nu (Join-Path $Vagrant 'packages')
         $options_file = "$package_name.$package_version.xml"
-        @{ Install = $Install; Uninstall = $Uninstall; Parameters = $Parameters } | Export-CliXML "$Vagrant\packages\$options_file"
+        @{ Install = $Install; Uninstall = $Uninstall; Parameters = $Parameters } | Export-CliXML ([System.IO.Path]::Combine($Vagrant, 'packages', $options_file))
         if ($VagrantOpen) {
             Start-Process powershell -Verb Open -ArgumentList "-NoProfile -NoExit -Command `$Env:http_proxy=`$Env:https_proxy=`$Env:ftp_proxy=`$Env:no_proxy=''; cd $Vagrant; vagrant up"
         } else {
diff --git a/AU/Public/Update-AUPackages.ps1 b/AU/Public/Update-AUPackages.ps1
index 8f60d195..e5709ad7 100644
--- a/AU/Public/Update-AUPackages.ps1
+++ b/AU/Public/Update-AUPackages.ps1
@@ -88,8 +88,8 @@ function Update-AUPackages {
 
     Remove-Job * -force #remove any previously run jobs
 
-    $tmp_dir = "$ENV:Temp\chocolatey\au"
-    New-Item -Type Directory -ea 0 $tmp_dir | Out-Null
+    $tmp_dir = ([System.IO.Path]::Combine([System.IO.Path]::GetTempPath(), "chocolatey", "au"))
+    New-Item -Type Directory  -ea 0 $tmp_dir | Out-Null
     Get-ChildItem $tmp_dir | Where-Object PSIsContainer -eq $false | Remove-Item   #clear tmp dir files
 
     $aup = Get-AUPackages $Name
@@ -128,7 +128,7 @@ function Update-AUPackages {
                         $pkg = [AUPackage]::new( (Get-AuPackages $($job.Name)) )
 
                         if ($ignored) {
-                            $pkg.Result = @('ignored', '') + (Get-Content "$tmp_dir\$($pkg.Name)" -ea 0)
+                            $pkg.Result = @('ignored', '') + (Get-Content ([System.IO.Path]::Combine($tmp_dir, $pkg.Name)) -ea 0)
                             $pkg.Ignored = $true
                             $pkg.IgnoreMessage = $pkg.Result[-1]
                         } elseif ($job.State -eq 'Stopped') {
@@ -210,7 +210,7 @@ function Update-AUPackages {
             $Options = $using:Options
 
             Set-Location $using:package_path
-            $out = "$using:tmp_dir\$using:package_name"
+            $out = (Join-Path $using:tmp_dir $using:package_name)
 
             $global:au_Timeout = $Options.Timeout
             $global:au_Force   = $Options.Force
@@ -269,8 +269,8 @@ function Update-AUPackages {
 function run_plugins() {
     if ($NoPlugins) { return }
 
-    Remove-Item -Force -Recurse $tmp_dir\plugins -ea ig
-    New-Item -Type Directory -Force $tmp_dir\plugins | Out-Null
+    Remove-Item -Force -Recurse (Join-Path $tmp_dir 'plugins') -ea ig
+    New-Item -Type Directory -Force (Join-Path $tmp_dir 'plugins') | Out-Null
     foreach ($key in $Options.Keys) {
         $params = $Options.$key
         if ($params -isnot [HashTable]) { continue }
@@ -285,8 +285,8 @@ function run_plugins() {
 
         try {
             Write-Host "`nRunning $key"
-            & $plugin_path $Info @params *>&1 | Tee-Object $tmp_dir\plugins\$key | Write-Host
-            $info.plugin_results.$key += Get-Content $tmp_dir\plugins\$key -ea ig
+            & $plugin_path $Info @params *>&1 | Tee-Object ([System.IO.Path]::Combine($tmp_dir, 'plugins', $key)) | Write-Host
+            $info.plugin_results.$key += Get-Content ([System.IO.Path]::Combine($tmp_dir, 'plugins', $key)) -ea ig
         } catch {
             $err_lines = $_.ToString() -split "`n"
             Write-Host "  ERROR: " $(foreach ($line in $err_lines) { "`n" + ' '*4 + $line })
diff --git a/AU/Public/Update-Package.ps1 b/AU/Public/Update-Package.ps1
index b99353e3..7fd7c1e7 100644
--- a/AU/Public/Update-Package.ps1
+++ b/AU/Public/Update-Package.ps1
@@ -250,7 +250,7 @@ function Update-Package {
         if ($WhatIf) { $package.Backup() }
         try {
             if (Test-Path Function:\au_BeforeUpdate) { 'Running au_BeforeUpdate' | result; au_BeforeUpdate $package | result }
-            if (!$NoReadme -and (Test-Path "$($package.Path)\README.md")) { Set-DescriptionFromReadme $package -SkipFirst 2 | result }        
+            if (!$NoReadme -and (Test-Path (Join-Path $package.Path 'README.md'))) { Set-DescriptionFromReadme $package -SkipFirst 2 | result }        
             update_files
             if (Test-Path Function:\au_AfterUpdate) { 'Running au_AfterUpdate' | result; au_AfterUpdate $package | result }