Use this PowerShell script to uninstall and remove all the custom solutions From http://sharepoint247.wordpress.com/2013/04/09/powershell-script-to-remove-all-custom-solutions-from-sharepoint-farm-solutions-store/

readme

Script Usage:

1. Copy paste the below script in a text file and save the file as say “CleanupFarmSolutionStore.ps1″.

2. Run SharePoint 2010 Management Shell and change directory to where you saved above file.

3. Run command as > .\CleanupFarmSolutionStore.ps1 -Confirm $false

Note: Setting parameter -Confirm to false will not ask for confirmation before uninstalling and removing the solution from farm solution store. Set it to true for asking the confirmation.

uninstallcustomsolution.ps1

#########################################################################################################
####    Author: Rahul G. Babar                                                                       ####
####    Purpose: Use this PowerShell script to uninstall and remove all the custom solutions from    ####
####             the SharePoint farm solution store.                                                 ####
####    Usage Example: .\CleanupFarmSolutionStore.ps1 -Confirm:$false                                ####
#########################################################################################################
 
[CmdletBinding()]
Param(
   [Parameter(Mandatory=$true,Position=1)]
   [bool]$Confirm
)
 
function LoadSharePointPowerShellEnvironment
{
    write-host "Setting up PowerShell environment for SharePoint" -foregroundcolor Yellow
    write-host
    Add-PSSnapin "Microsoft.SharePoint.PowerShell" -ErrorAction SilentlyContinue
    write-host "SharePoint PowerShell Snapin loaded." -foregroundcolor Green
    write-host
}
 
LoadSharePointPowerShellEnvironment
 
$AdminServiceName = "SPAdminV4"
$WasAdminServiceRunning = $true;
 
if ($(Get-Service $AdminServiceName).Status -eq "Stopped")
{
    write-host "[[STEP]] Starting SharePoint Administration Service since it is not already started." -foregroundcolor Yellow
    write-host
 
    $WasAdminServiceRunning = $false;
    Start-Service $AdminServiceName
 
    write-host "[[STEP]] SharePoint Administration Service Started" -foregroundcolor Green
    write-host
}
 
Start-SPAssignment -Global;
$solutions = Get-SPSolution
foreach($solution in $solutions)
{
    if($solution -ne $null)
    {
        $solutionName = $solution.Name
        if($solution.Deployed)
        {
            Write-Host "Uninstalling solution $solutionName..." -ForegroundColor Yellow
            write-host
            if($solution.DeployedWebApplications.Count -gt 0)
            {
                Uninstall-SPSolution -Identity $solution -AllWebApplications -Confirm:$Confirm
            }
            else
            {
                Uninstall-SPSolution -Identity $solution -Local:$true -Confirm:$Confirm
            }
            do
            {
                Start-Sleep 5;
                $solution = Get-SPSolution $solution;
            } while($solution.JobExists -or $solution.Deployed)
            Write-Host "Unistalled solution $solutionName successfully." -ForegroundColor Green
            write-host
        }
 
        Write-Host "Removing solution $solutionName..." -ForegroundColor Yellow
        write-host
        Remove-SPSolution -Identity $solution -Confirm:$Confirm
        do
        {
            Start-Sleep 5;
            $solution = Get-SPSolution $solution -ErrorAction SilentlyContinue
        } while($solution -ne $null)
        Write-Host "Removed solution $solutionName successfully." -ForegroundColor Green
        write-host
    }
}
Stop-SPAssignment -Global;
 
if (-not $WasAdminServiceRunning)
{
    write-host "[[STEP]] Stopping SharePoint Administration Service." -foregroundcolor Yellow
    write-host
        Stop-Service $AdminServiceName
    write-host "[[STEP]] SharePoint Administration Service Stopped." -foregroundcolor Green
    write-host
}
 
Write-Host "Farm solution store cleanup finished" -ForegroundColor Green